Merge remote-tracking branch 'origin/V2' into

codex/add-pdf-to-json-and-json-to-pdf-features

app/common/src/main/java/stirling/software/common/annotations/AutoJobPostMapping.java

@@ -3,6 +3,7 @@ package stirling.software.common.annotations;
 import java.lang.annotation.*;
 
 import org.springframework.core.annotation.AliasFor;
+import org.springframework.http.MediaType;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
 
@@ -40,7 +41,7 @@ public @interface AutoJobPostMapping {
 
     /** MIME types this endpoint accepts. Defaults to {@code multipart/form-data}. */
     @AliasFor(annotation = RequestMapping.class, attribute = "consumes")
-    String[] consumes() default {"multipart/form-data"};
+    String[] consumes() default {MediaType.MULTIPART_FORM_DATA_VALUE};
 
     /**
      * Maximum execution time in milliseconds before the job is aborted. A negative value means "use

app/common/src/main/java/stirling/software/common/aop/AutoJobAspect.java

@@ -19,7 +19,6 @@ import lombok.extern.slf4j.Slf4j;
 
 import stirling.software.common.annotations.AutoJobPostMapping;
 import stirling.software.common.model.api.PDFFile;
-import stirling.software.common.service.FileOrUploadService;
 import stirling.software.common.service.FileStorage;
 import stirling.software.common.service.JobExecutorService;
 
@@ -34,7 +33,6 @@ public class AutoJobAspect {
 
     private final JobExecutorService jobExecutorService;
     private final HttpServletRequest request;
-    private final FileOrUploadService fileOrUploadService;
     private final FileStorage fileStorage;
 
     @Around("@annotation(autoJobPostMapping)")
@@ -53,7 +51,8 @@ public class AutoJobAspect {
         boolean trackProgress = autoJobPostMapping.trackProgress();
 
         log.debug(
-                "AutoJobPostMapping execution with async={}, timeout={}, retryCount={}, trackProgress={}",
+                "AutoJobPostMapping execution with async={}, timeout={}, retryCount={},"
+                        + " trackProgress={}",
                 async,
                 timeout > 0 ? timeout : "default",
                 retryCount,
@@ -148,7 +147,8 @@ public class AutoJobAspect {
                         } catch (Throwable ex) {
                             lastException = ex;
                             log.error(
-                                    "AutoJobAspect caught exception during job execution (attempt {}/{}): {}",
+                                    "AutoJobAspect caught exception during job execution (attempt"
+                                            + " {}/{}): {}",
                                     currentAttempt,
                                     maxRetries,
                                     ex.getMessage(),

app/common/src/main/java/stirling/software/common/configuration/ConfigInitializer.java

@@ -23,10 +23,30 @@ import stirling.software.common.util.YamlHelper;
 @Slf4j
 public class ConfigInitializer {
 
+    private static final int MIN_SETTINGS_FILE_LINES = 31;
+
     public void ensureConfigExists() throws IOException, URISyntaxException {
         // 1) If settings file doesn't exist, create from template
         Path destPath = Paths.get(InstallationPathConfig.getSettingsPath());
-        if (Files.notExists(destPath)) {
+
+        boolean settingsFileExists = Files.exists(destPath);
+
+        long lineCount = settingsFileExists ? Files.readAllLines(destPath).size() : 0;
+
+        log.info("Current settings file line count: {}", lineCount);
+
+        if (!settingsFileExists || lineCount < MIN_SETTINGS_FILE_LINES) {
+            if (settingsFileExists) {
+                // move settings.yml to settings.yml.{timestamp}.bak
+                Path backupPath =
+                        Paths.get(
+                                InstallationPathConfig.getSettingsPath()
+                                        + "."
+                                        + System.currentTimeMillis()
+                                        + ".bak");
+                Files.move(destPath, backupPath, StandardCopyOption.REPLACE_EXISTING);
+                log.info("Moved existing settings file to backup: {}", backupPath);
+            }
             Files.createDirectories(destPath.getParent());
             try (InputStream in =
                     getClass().getClassLoader().getResourceAsStream("settings.yml.template")) {

app/common/src/main/java/stirling/software/common/configuration/InstallationPathConfig.java

@@ -14,12 +14,17 @@ public class InstallationPathConfig {
     private static final String CONFIG_PATH;
     private static final String CUSTOM_FILES_PATH;
     private static final String CLIENT_WEBUI_PATH;
-    private static final String SCRIPTS_PATH;
     private static final String PIPELINE_PATH;
 
     // Config paths
     private static final String SETTINGS_PATH;
     private static final String CUSTOM_SETTINGS_PATH;
+    private static final String SCRIPTS_PATH;
+    private static final String BACKUP_PATH;
+
+    // Backup paths
+    private static final String BACKUP_DB_PATH;
+    private static final String BACKUP_PRIVATE_KEY_PATH;
 
     // Custom file paths
     private static final String STATIC_PATH;
@@ -41,6 +46,11 @@ public class InstallationPathConfig {
         SETTINGS_PATH = CONFIG_PATH + "settings.yml";
         CUSTOM_SETTINGS_PATH = CONFIG_PATH + "custom_settings.yml";
         SCRIPTS_PATH = CONFIG_PATH + "scripts" + File.separator;
+        BACKUP_PATH = CONFIG_PATH + "backup" + File.separator;
+
+        // Initialize backup paths
+        BACKUP_DB_PATH = BACKUP_PATH + "db" + File.separator;
+        BACKUP_PRIVATE_KEY_PATH = BACKUP_PATH + "keys" + File.separator;
 
         // Initialize custom file paths
         STATIC_PATH = CUSTOM_FILES_PATH + "static" + File.separator;
@@ -124,6 +134,10 @@ public class InstallationPathConfig {
     }
 
     public static String getPrivateKeyPath() {
-        return PRIVATE_KEY_PATH;
+        return BACKUP_PRIVATE_KEY_PATH;
+    }
+
+    public static String getBackupPath() {
+        return BACKUP_DB_PATH;
     }
 }

app/common/src/main/java/stirling/software/common/model/ApplicationProperties.java

@@ -41,6 +41,7 @@ import stirling.software.common.model.oauth2.GitHubProvider;
 import stirling.software.common.model.oauth2.GoogleProvider;
 import stirling.software.common.model.oauth2.KeycloakProvider;
 import stirling.software.common.model.oauth2.Provider;
+import stirling.software.common.service.SsrfProtectionService.SsrfProtectionLevel;
 import stirling.software.common.util.ValidationUtils;
 
 @Data
@@ -72,11 +73,11 @@ public class ApplicationProperties {
     public PropertySource<?> dynamicYamlPropertySource(ConfigurableEnvironment environment)
             throws IOException {
         String configPath = InstallationPathConfig.getSettingsPath();
-        log.debug("Attempting to load settings from: " + configPath);
+        log.debug("Attempting to load settings from: {}", configPath);
 
         File file = new File(configPath);
         if (!file.exists()) {
-            log.error("Warning: Settings file does not exist at: " + configPath);
+            log.error("Warning: Settings file does not exist at: {}", configPath);
         }
 
         Resource resource = new FileSystemResource(configPath);
@@ -89,7 +90,7 @@ public class ApplicationProperties {
                 new YamlPropertySourceFactory().createPropertySource(null, encodedResource);
         environment.getPropertySources().addFirst(propertySource);
 
-        log.debug("Loaded properties: " + propertySource.getSource());
+        log.debug("Loaded properties: {}", propertySource.getSource());
 
         return propertySource;
     }
@@ -365,7 +366,12 @@ public class ApplicationProperties {
         private CustomPaths customPaths = new CustomPaths();
         private String fileUploadLimit;
         private TempFileManagement tempFileManagement = new TempFileManagement();
+        private DatabaseBackup databaseBackup = new DatabaseBackup();
         private List<String> corsAllowedOrigins = new ArrayList<>();
+        private String
+                frontendUrl; // Base URL for frontend (used for invite links, etc.). If not set,
+
+        // falls back to backend URL.
 
         public boolean isAnalyticsEnabled() {
             return this.getEnableAnalytics() != null && this.getEnableAnalytics();
@@ -384,6 +390,11 @@ public class ApplicationProperties {
         }
     }
 
+    @Data
+    public static class DatabaseBackup {
+        private String cron = "0 0 0 * * ?"; // daily at midnight
+    }
+
     @Data
     public static class CustomPaths {
         private Pipeline pipeline = new Pipeline();
@@ -420,17 +431,19 @@ public class ApplicationProperties {
 
         @JsonIgnore
         public String getBaseTmpDir() {
-            return baseTmpDir != null && !baseTmpDir.isEmpty()
-                    ? baseTmpDir
-                    : java.lang.System.getProperty("java.io.tmpdir").replaceAll("/+$", "")
-                            + "/stirling-pdf";
+            if (baseTmpDir != null && !baseTmpDir.isEmpty()) {
+                return baseTmpDir;
+            }
+            String tmp = java.lang.System.getProperty("java.io.tmpdir");
+            return new File(tmp, "stirling-pdf").getPath();
         }
 
         @JsonIgnore
         public String getLibreofficeDir() {
-            return libreofficeDir != null && !libreofficeDir.isEmpty()
-                    ? libreofficeDir
-                    : getBaseTmpDir() + "/libreoffice";
+            if (libreofficeDir != null && !libreofficeDir.isEmpty()) {
+                return libreofficeDir;
+            }
+            return new File(getBaseTmpDir(), "libreoffice").getPath();
         }
     }
 
@@ -441,7 +454,7 @@ public class ApplicationProperties {
         @Data
         public static class UrlSecurity {
             private boolean enabled = true;
-            private String level = "MEDIUM"; // MAX, MEDIUM, OFF
+            private SsrfProtectionLevel level = SsrfProtectionLevel.MEDIUM; // MAX, MEDIUM, OFF
             private List<String> allowedDomains = new ArrayList<>();
             private List<String> blockedDomains = new ArrayList<>();
             private List<String> internalTlds =
@@ -494,9 +507,7 @@ public class ApplicationProperties {
         private List<String> languages;
 
         public String getAppNameNavbar() {
-            return appNameNavbar != null && appNameNavbar.trim().length() > 0
-                    ? appNameNavbar
-                    : null;
+            return appNameNavbar != null && !appNameNavbar.trim().isEmpty() ? appNameNavbar : null;
         }
     }
 
@@ -549,6 +560,7 @@ public class ApplicationProperties {
     public static class Mail {
         private boolean enabled;
         private boolean enableInvites = false;
+        private int inviteLinkExpiryHours = 72; // Default: 72 hours (3 days)
         private String host;
         private int port;
         private String username;

app/common/src/main/java/stirling/software/common/model/FileInfo.java

@@ -8,9 +8,11 @@ import java.util.Locale;
 
 import lombok.AllArgsConstructor;
 import lombok.Data;
+import lombok.NoArgsConstructor;
 
-@AllArgsConstructor
 @Data
+@NoArgsConstructor
+@AllArgsConstructor
 public class FileInfo {
     private static final DateTimeFormatter DATE_FORMATTER =
             DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");

app/common/src/main/java/stirling/software/common/model/InputStreamTemplateResource.java

@@ -4,14 +4,12 @@ package stirling.software.common.model;
  * This class will be removed when frontend migration to React is complete
 
 
-public class InputStreamTemplateResource implements ITemplateResource {
-    private InputStream inputStream;
-    private String characterEncoding;
 
-    public InputStreamTemplateResource(InputStream inputStream, String characterEncoding) {
-        this.inputStream = inputStream;
-        this.characterEncoding = characterEncoding;
-    }
+@RequiredArgsConstructor
+@Getter
+public class InputStreamTemplateResource implements ITemplateResource {
+    private final InputStream inputStream;
+    private final String characterEncoding;
 
     @Override
     public Reader reader() throws IOException {

app/common/src/main/java/stirling/software/common/model/PdfMetadata.java

@@ -1,12 +1,16 @@
 package stirling.software.common.model;
 
-import java.util.Calendar;
+import java.time.ZonedDateTime;
 
+import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
+import lombok.NoArgsConstructor;
 
 @Data
 @Builder
+@NoArgsConstructor
+@AllArgsConstructor
 public class PdfMetadata {
     private String author;
     private String producer;
@@ -14,6 +18,6 @@ public class PdfMetadata {
     private String creator;
     private String subject;
     private String keywords;
-    private Calendar creationDate;
-    private Calendar modificationDate;
+    private ZonedDateTime creationDate;
+    private ZonedDateTime modificationDate;
 }

app/common/src/main/java/stirling/software/common/model/api/PDFFile.java

@@ -1,5 +1,6 @@
 package stirling.software.common.model.api;
 
+import org.springframework.http.MediaType;
 import org.springframework.web.multipart.MultipartFile;
 
 import io.swagger.v3.oas.annotations.media.Schema;
@@ -15,7 +16,11 @@ import lombok.NoArgsConstructor;
 @EqualsAndHashCode
 @Schema(description = "PDF file input - either upload a file or provide a server-side file ID")
 public class PDFFile {
-    @Schema(description = "The input PDF file", format = "binary")
+
+    @Schema(
+            description = "The input PDF file",
+            contentMediaType = MediaType.APPLICATION_PDF_VALUE,
+            format = "binary")
     private MultipartFile fileInput;
 
     @Schema(

app/common/src/main/java/stirling/software/common/model/api/misc/ReplaceAndInvert.java

@@ -4,4 +4,5 @@ public enum ReplaceAndInvert {
     HIGH_CONTRAST_COLOR,
     CUSTOM_COLOR,
     FULL_INVERSION,
+    COLOR_SPACE_CONVERSION,
 }

app/common/src/main/java/stirling/software/common/service/JobExecutorService.java

@@ -23,6 +23,7 @@ import lombok.extern.slf4j.Slf4j;
 
 import stirling.software.common.model.job.JobResponse;
 import stirling.software.common.util.ExecutorFactory;
+import stirling.software.common.util.RegexPatternUtils;
 
 /** Service for executing jobs asynchronously or synchronously */
 @Service
@@ -274,7 +275,8 @@ public class JobExecutorService {
             if (result instanceof byte[]) {
                 // Store byte array directly to disk to avoid double memory consumption
                 String fileId = fileStorage.storeBytes((byte[]) result, "result.pdf");
-                taskManager.setFileResult(jobId, fileId, "result.pdf", "application/pdf");
+                taskManager.setFileResult(
+                        jobId, fileId, "result.pdf", MediaType.APPLICATION_PDF_VALUE);
                 log.debug("Stored byte[] result with fileId: {}", fileId);
 
                 // Let the byte array get collected naturally in the next GC cycle
@@ -286,7 +288,7 @@ public class JobExecutorService {
                 if (body instanceof byte[]) {
                     // Extract filename from content-disposition header if available
                     String filename = "result.pdf";
-                    String contentType = "application/pdf";
+                    String contentType = MediaType.APPLICATION_PDF_VALUE;
 
                     if (response.getHeaders().getContentDisposition() != null) {
                         String disposition =
@@ -299,8 +301,10 @@ public class JobExecutorService {
                         }
                     }
 
-                    if (response.getHeaders().getContentType() != null) {
-                        contentType = response.getHeaders().getContentType().toString();
+                    MediaType mediaType = response.getHeaders().getContentType();
+
+                    if (mediaType != null) {
+                        contentType = mediaType.toString();
                     }
 
                     // Store byte array directly to disk
@@ -321,7 +325,7 @@ public class JobExecutorService {
                             if (fileId != null && !fileId.isEmpty()) {
                                 // Try to get filename and content type
                                 String filename = "result.pdf";
-                                String contentType = "application/pdf";
+                                String contentType = MediaType.APPLICATION_PDF_VALUE;
 
                                 try {
                                     java.lang.reflect.Method getOriginalFileName =
@@ -362,8 +366,7 @@ public class JobExecutorService {
                     // Store generic result
                     taskManager.setResult(jobId, body);
                 }
-            } else if (result instanceof MultipartFile) {
-                MultipartFile file = (MultipartFile) result;
+            } else if (result instanceof MultipartFile file) {
                 String fileId = fileStorage.storeFile(file);
                 taskManager.setFileResult(
                         jobId, fileId, file.getOriginalFilename(), file.getContentType());
@@ -380,7 +383,7 @@ public class JobExecutorService {
                         if (fileId != null && !fileId.isEmpty()) {
                             // Try to get filename and content type
                             String filename = "result.pdf";
-                            String contentType = "application/pdf";
+                            String contentType = MediaType.APPLICATION_PDF_VALUE;
 
                             try {
                                 java.lang.reflect.Method getOriginalFileName =
@@ -443,9 +446,8 @@ public class JobExecutorService {
                             HttpHeaders.CONTENT_DISPOSITION,
                             "form-data; name=\"attachment\"; filename=\"result.pdf\"")
                     .body(result);
-        } else if (result instanceof MultipartFile) {
+        } else if (result instanceof MultipartFile file) {
             // Return MultipartFile content
-            MultipartFile file = (MultipartFile) result;
             return ResponseEntity.ok()
                     .contentType(MediaType.parseMediaType(file.getContentType()))
                     .header(
@@ -472,8 +474,16 @@ public class JobExecutorService {
         }
 
         try {
-            String value = timeout.replaceAll("[^\\d.]", "");
-            String unit = timeout.replaceAll("[\\d.]", "");
+            String value =
+                    RegexPatternUtils.getInstance()
+                            .getNonDigitDotPattern()
+                            .matcher(timeout)
+                            .replaceAll("");
+            String unit =
+                    RegexPatternUtils.getInstance()
+                            .getDigitDotPattern()
+                            .matcher(timeout)
+                            .replaceAll("");
 
             double numericValue = Double.parseDouble(value);
 

app/common/src/main/java/stirling/software/common/service/PdfMetadataService.java

@@ -1,5 +1,9 @@
 package stirling.software.common.service;
 
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
 import java.util.Calendar;
 
 import org.apache.pdfbox.pdmodel.PDDocument;
@@ -29,17 +33,19 @@ public class PdfMetadataService {
         this.runningProOrHigher = runningProOrHigher;
     }
 
-    public PdfMetadata extractMetadataFromPdf(PDDocument pdf) {
-        return PdfMetadata.builder()
-                .author(pdf.getDocumentInformation().getAuthor())
-                .producer(pdf.getDocumentInformation().getProducer())
-                .title(pdf.getDocumentInformation().getTitle())
-                .creator(pdf.getDocumentInformation().getCreator())
-                .subject(pdf.getDocumentInformation().getSubject())
-                .keywords(pdf.getDocumentInformation().getKeywords())
-                .creationDate(pdf.getDocumentInformation().getCreationDate())
-                .modificationDate(pdf.getDocumentInformation().getModificationDate())
-                .build();
+    /**
+     * Converts ZonedDateTime to Calendar for PDFBox compatibility.
+     *
+     * @param zonedDateTime the ZonedDateTime to convert
+     * @return Calendar instance or null if input is null
+     */
+    public static Calendar toCalendar(ZonedDateTime zonedDateTime) {
+        if (zonedDateTime == null) {
+            return null;
+        }
+        Calendar calendar = Calendar.getInstance();
+        calendar.setTimeInMillis(zonedDateTime.toInstant().toEpochMilli());
+        return calendar;
     }
 
     public void setDefaultMetadata(PDDocument pdf) {
@@ -58,6 +64,52 @@ public class PdfMetadataService {
         setCommonMetadata(pdf, pdfMetadata);
     }
 
+    /**
+     * Parses a date string and converts it to Calendar for PDFBox compatibility.
+     *
+     * @param dateString the date string in "yyyy/MM/dd HH:mm:ss" format
+     * @return Calendar instance or null if parsing fails or input is empty
+     */
+    public static Calendar parseToCalendar(String dateString) {
+        if (dateString == null || dateString.trim().isEmpty()) {
+            return null;
+        }
+        try {
+            DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss");
+            ZonedDateTime zonedDateTime =
+                    LocalDateTime.parse(dateString, formatter).atZone(ZoneId.systemDefault());
+            return toCalendar(zonedDateTime);
+        } catch (Exception e) {
+            return null;
+        }
+    }
+
+    public PdfMetadata extractMetadataFromPdf(PDDocument pdf) {
+        Calendar creationCal = pdf.getDocumentInformation().getCreationDate();
+        Calendar modificationCal = pdf.getDocumentInformation().getModificationDate();
+
+        ZonedDateTime creationDate =
+                creationCal != null
+                        ? ZonedDateTime.ofInstant(creationCal.toInstant(), ZoneId.systemDefault())
+                        : null;
+        ZonedDateTime modificationDate =
+                modificationCal != null
+                        ? ZonedDateTime.ofInstant(
+                                modificationCal.toInstant(), ZoneId.systemDefault())
+                        : null;
+
+        return PdfMetadata.builder()
+                .author(pdf.getDocumentInformation().getAuthor())
+                .producer(pdf.getDocumentInformation().getProducer())
+                .title(pdf.getDocumentInformation().getTitle())
+                .creator(pdf.getDocumentInformation().getCreator())
+                .subject(pdf.getDocumentInformation().getSubject())
+                .keywords(pdf.getDocumentInformation().getKeywords())
+                .creationDate(creationDate)
+                .modificationDate(modificationDate)
+                .build();
+    }
+
     private void setNewDocumentMetadata(PDDocument pdf, PdfMetadata pdfMetadata) {
 
         String creator = stirlingPDFLabel;
@@ -79,7 +131,13 @@ public class PdfMetadataService {
         }
 
         pdf.getDocumentInformation().setCreator(creator);
-        pdf.getDocumentInformation().setCreationDate(Calendar.getInstance());
+
+        // Use existing creation date if available, otherwise create new one
+        Calendar creationCal =
+                pdfMetadata.getCreationDate() != null
+                        ? toCalendar(pdfMetadata.getCreationDate())
+                        : Calendar.getInstance();
+        pdf.getDocumentInformation().setCreationDate(creationCal);
     }
 
     private void setCommonMetadata(PDDocument pdf, PdfMetadata pdfMetadata) {
@@ -88,7 +146,13 @@ public class PdfMetadataService {
         pdf.getDocumentInformation().setProducer(stirlingPDFLabel);
         pdf.getDocumentInformation().setSubject(pdfMetadata.getSubject());
         pdf.getDocumentInformation().setKeywords(pdfMetadata.getKeywords());
-        pdf.getDocumentInformation().setModificationDate(Calendar.getInstance());
+
+        // Convert ZonedDateTime to Calendar for PDFBox compatibility
+        Calendar modificationCal =
+                pdfMetadata.getModificationDate() != null
+                        ? toCalendar(pdfMetadata.getModificationDate())
+                        : Calendar.getInstance();
+        pdf.getDocumentInformation().setModificationDate(modificationCal);
 
         String author = pdfMetadata.getAuthor();
         if (applicationProperties

app/common/src/main/java/stirling/software/common/service/SsrfProtectionService.java

@@ -1,5 +1,7 @@
 package stirling.software.common.service;
 
+import java.net.Inet4Address;
+import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.net.URI;
 import java.net.UnknownHostException;
@@ -11,6 +13,7 @@ import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
 import stirling.software.common.model.ApplicationProperties;
+import stirling.software.common.util.RegexPatternUtils;
 
 @Service
 @RequiredArgsConstructor
@@ -20,8 +23,9 @@ public class SsrfProtectionService {
     private final ApplicationProperties applicationProperties;
 
     private static final Pattern DATA_URL_PATTERN =
-            Pattern.compile("^data:.*", Pattern.CASE_INSENSITIVE);
-    private static final Pattern FRAGMENT_PATTERN = Pattern.compile("^#.*");
+            RegexPatternUtils.getInstance().getPattern("^data:.*", Pattern.CASE_INSENSITIVE);
+    private static final Pattern FRAGMENT_PATTERN =
+            RegexPatternUtils.getInstance().getPattern("^#.*");
 
     public enum SsrfProtectionLevel {
         OFF, // No SSRF protection - allows all URLs
@@ -51,21 +55,17 @@ public class SsrfProtectionService {
 
         SsrfProtectionLevel level = parseProtectionLevel(config.getLevel());
 
-        switch (level) {
-            case OFF:
-                return true;
-            case MAX:
-                return isMaxSecurityAllowed(trimmedUrl, config);
-            case MEDIUM:
-                return isMediumSecurityAllowed(trimmedUrl, config);
-            default:
-                return false;
-        }
+        return switch (level) {
+            case OFF -> true;
+            case MAX -> isMaxSecurityAllowed(trimmedUrl, config);
+            case MEDIUM -> isMediumSecurityAllowed(trimmedUrl, config);
+            default -> false;
+        };
     }
 
-    private SsrfProtectionLevel parseProtectionLevel(String level) {
+    private SsrfProtectionLevel parseProtectionLevel(SsrfProtectionLevel level) {
         try {
-            return SsrfProtectionLevel.valueOf(level.toUpperCase());
+            return SsrfProtectionLevel.valueOf(level.name());
         } catch (IllegalArgumentException e) {
             log.warn("Invalid SSRF protection level '{}', defaulting to MEDIUM", level);
             return SsrfProtectionLevel.MEDIUM;
@@ -172,15 +172,62 @@ public class SsrfProtectionService {
     }
 
     private boolean isPrivateAddress(InetAddress address) {
-        return address.isSiteLocalAddress()
-                || address.isAnyLocalAddress()
-                || isPrivateIPv4Range(address.getHostAddress());
+        if (address.isAnyLocalAddress() || address.isLoopbackAddress()) {
+            return true;
+        }
+
+        if (address instanceof Inet4Address) {
+            return isPrivateIPv4Range(address.getHostAddress());
+        }
+
+        if (address instanceof Inet6Address addr6) {
+            if (addr6.isLinkLocalAddress() || addr6.isSiteLocalAddress()) {
+                return true;
+            }
+
+            byte[] bytes = addr6.getAddress();
+            if (isIpv4MappedAddress(bytes)) {
+                String ipv4 =
+                        (bytes[12] & 0xff)
+                                + "."
+                                + (bytes[13] & 0xff)
+                                + "."
+                                + (bytes[14] & 0xff)
+                                + "."
+                                + (bytes[15] & 0xff);
+                return isPrivateIPv4Range(ipv4);
+            }
+
+            int firstByte = bytes[0] & 0xff;
+            // Check for IPv6 unique local addresses (fc00::/7)
+            if ((firstByte & 0xfe) == 0xfc) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private boolean isIpv4MappedAddress(byte[] addr) {
+        if (addr.length != 16) {
+            return false;
+        }
+        for (int i = 0; i < 10; i++) {
+            if (addr[i] != 0) {
+                return false;
+            }
+        }
+        // For IPv4-mapped IPv6 addresses, bytes 10 and 11 must be 0xff (i.e., address is
+        // ::ffff:w.x.y.z)
+        return addr[10] == (byte) 0xff && addr[11] == (byte) 0xff;
     }
 
     private boolean isPrivateIPv4Range(String ip) {
+        // Includes RFC1918, loopback, link-local, and unspecified addresses
         return ip.startsWith("10.")
                 || ip.startsWith("192.168.")
                 || (ip.startsWith("172.") && isInRange172(ip))
+                || ip.startsWith("169.254.")
                 || ip.startsWith("127.")
                 || "0.0.0.0".equals(ip);
     }
@@ -192,17 +239,31 @@ public class SsrfProtectionService {
                 int secondOctet = Integer.parseInt(parts[1]);
                 return secondOctet >= 16 && secondOctet <= 31;
             } catch (NumberFormatException e) {
-                return false;
             }
         }
         return false;
     }
 
     private boolean isCloudMetadataAddress(String ip) {
+        String normalizedIp = normalizeIpv4MappedAddress(ip);
         // Cloud metadata endpoints for AWS, GCP, Azure, Oracle Cloud, and IBM Cloud
-        return ip.startsWith("169.254.169.254") // AWS/GCP/Azure
-                || ip.startsWith("fd00:ec2::254") // AWS IPv6
-                || ip.startsWith("169.254.169.253") // Oracle Cloud
-                || ip.startsWith("169.254.169.250"); // IBM Cloud
+        return normalizedIp.startsWith("169.254.169.254") // AWS/GCP/Azure
+                || normalizedIp.startsWith("fd00:ec2::254") // AWS IPv6
+                || normalizedIp.startsWith("169.254.169.253") // Oracle Cloud
+                || normalizedIp.startsWith("169.254.169.250"); // IBM Cloud
+    }
+
+    private String normalizeIpv4MappedAddress(String ip) {
+        if (ip == null) {
+            return "";
+        }
+        if (ip.startsWith("::ffff:")) {
+            return ip.substring(7);
+        }
+        int lastColon = ip.lastIndexOf(':');
+        if (lastColon >= 0 && ip.indexOf('.') > lastColon) {
+            return ip.substring(lastColon + 1);
+        }
+        return ip;
     }
 }

app/common/src/main/java/stirling/software/common/service/TempFileCleanupService.java

@@ -23,6 +23,7 @@ import lombok.extern.slf4j.Slf4j;
 
 import stirling.software.common.model.ApplicationProperties;
 import stirling.software.common.util.GeneralUtils;
+import stirling.software.common.util.RegexPatternUtils;
 import stirling.software.common.util.TempFileManager;
 import stirling.software.common.util.TempFileRegistry;
 
@@ -61,8 +62,14 @@ public class TempFileCleanupService {
     // File patterns that identify common system temp files
     private static final Predicate<String> IS_SYSTEM_TEMP_FILE =
             fileName ->
-                    fileName.matches("lu\\d+[a-z0-9]*\\.tmp")
-                            || fileName.matches("ocr_process\\d+")
+                    RegexPatternUtils.getInstance()
+                                    .getSystemTempFile1Pattern()
+                                    .matcher(fileName)
+                                    .matches()
+                            || RegexPatternUtils.getInstance()
+                                    .getSystemTempFile2Pattern()
+                                    .matcher(fileName)
+                                    .matches()
                             || (fileName.startsWith("tmp") && !fileName.contains("jetty"))
                             || fileName.startsWith("OSL_PIPE_")
                             || (fileName.endsWith(".tmp") && !fileName.contains("jetty"));

app/common/src/main/java/stirling/software/common/util/CbrUtils.java

@@ -0,0 +1,258 @@
+package stirling.software.common.util;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.List;
+
+import org.apache.commons.io.FilenameUtils;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.PDPageContentStream;
+import org.apache.pdfbox.pdmodel.common.PDRectangle;
+import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
+import org.springframework.web.multipart.MultipartFile;
+
+import com.github.junrar.Archive;
+import com.github.junrar.exception.CorruptHeaderException;
+import com.github.junrar.exception.RarException;
+import com.github.junrar.rarfile.FileHeader;
+
+import lombok.experimental.UtilityClass;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.common.service.CustomPDFDocumentFactory;
+
+@Slf4j
+@UtilityClass
+public class CbrUtils {
+
+    public byte[] convertCbrToPdf(
+            MultipartFile cbrFile,
+            CustomPDFDocumentFactory pdfDocumentFactory,
+            TempFileManager tempFileManager)
+            throws IOException {
+        return convertCbrToPdf(cbrFile, pdfDocumentFactory, tempFileManager, false);
+    }
+
+    public byte[] convertCbrToPdf(
+            MultipartFile cbrFile,
+            CustomPDFDocumentFactory pdfDocumentFactory,
+            TempFileManager tempFileManager,
+            boolean optimizeForEbook)
+            throws IOException {
+
+        validateCbrFile(cbrFile);
+
+        try (TempFile tempFile = new TempFile(tempFileManager, ".cbr")) {
+            cbrFile.transferTo(tempFile.getFile());
+
+            try (PDDocument document = pdfDocumentFactory.createNewDocument()) {
+
+                Archive archive;
+                try {
+                    archive = new Archive(tempFile.getFile());
+                } catch (CorruptHeaderException e) {
+                    log.warn(
+                            "Failed to open CBR/RAR archive due to corrupt header: {}",
+                            e.getMessage());
+                    throw ExceptionUtils.createIllegalArgumentException(
+                            "error.invalidFormat",
+                            "Invalid or corrupted CBR/RAR archive. "
+                                    + "The file may be corrupted, use an unsupported RAR format (RAR5+), "
+                                    + "or may not be a valid RAR archive. "
+                                    + "Please ensure the file is a valid RAR archive.");
+                } catch (RarException e) {
+                    log.warn("Failed to open CBR/RAR archive: {}", e.getMessage());
+                    String errorMessage;
+                    String exMessage = e.getMessage() != null ? e.getMessage() : "";
+
+                    if (exMessage.contains("encrypted")) {
+                        errorMessage = "Encrypted CBR/RAR archives are not supported.";
+                    } else if (exMessage.isEmpty()) {
+                        errorMessage =
+                                "Invalid CBR/RAR archive. "
+                                        + "The file may be encrypted, corrupted, or use an unsupported format.";
+                    } else {
+                        errorMessage =
+                                "Invalid CBR/RAR archive: "
+                                        + exMessage
+                                        + ". The file may be encrypted, corrupted, or use an unsupported format.";
+                    }
+                    throw ExceptionUtils.createIllegalArgumentException(
+                            "error.invalidFormat", errorMessage);
+                } catch (IOException e) {
+                    log.warn("IO error reading CBR/RAR archive: {}", e.getMessage());
+                    throw ExceptionUtils.createFileProcessingException("CBR extraction", e);
+                }
+
+                List<ImageEntryData> imageEntries = new ArrayList<>();
+
+                try {
+                    for (FileHeader fileHeader : archive) {
+                        if (!fileHeader.isDirectory() && isImageFile(fileHeader.getFileName())) {
+                            try (InputStream is = archive.getInputStream(fileHeader)) {
+                                ByteArrayOutputStream baos = new ByteArrayOutputStream();
+                                is.transferTo(baos);
+                                imageEntries.add(
+                                        new ImageEntryData(
+                                                fileHeader.getFileName(), baos.toByteArray()));
+                            } catch (Exception e) {
+                                log.warn(
+                                        "Error reading image {}: {}",
+                                        fileHeader.getFileName(),
+                                        e.getMessage());
+                            }
+                        }
+                    }
+                } finally {
+                    try {
+                        archive.close();
+                    } catch (IOException e) {
+                        log.warn("Error closing CBR/RAR archive: {}", e.getMessage());
+                    }
+                }
+
+                imageEntries.sort(
+                        Comparator.comparing(ImageEntryData::name, new NaturalOrderComparator()));
+
+                if (imageEntries.isEmpty()) {
+                    throw ExceptionUtils.createIllegalArgumentException(
+                            "error.fileProcessing",
+                            "No valid images found in the CBR file. The archive may be empty or contain no supported image formats.");
+                }
+
+                for (ImageEntryData imageEntry : imageEntries) {
+                    try {
+                        PDImageXObject pdImage =
+                                PDImageXObject.createFromByteArray(
+                                        document, imageEntry.data(), imageEntry.name());
+                        PDPage page =
+                                new PDPage(
+                                        new PDRectangle(pdImage.getWidth(), pdImage.getHeight()));
+                        document.addPage(page);
+                        try (PDPageContentStream contentStream =
+                                new PDPageContentStream(document, page)) {
+                            contentStream.drawImage(pdImage, 0, 0);
+                        }
+                    } catch (IOException e) {
+                        log.warn(
+                                "Error processing image {}: {}", imageEntry.name(), e.getMessage());
+                    }
+                }
+
+                if (document.getNumberOfPages() == 0) {
+                    throw ExceptionUtils.createIllegalArgumentException(
+                            "error.fileProcessing",
+                            "No images could be processed from the CBR file. All images may be corrupted or in unsupported formats.");
+                }
+
+                ByteArrayOutputStream baos = new ByteArrayOutputStream();
+                document.save(baos);
+                byte[] pdfBytes = baos.toByteArray();
+
+                // Apply Ghostscript optimization if requested
+                if (optimizeForEbook) {
+                    try {
+                        return GeneralUtils.optimizePdfWithGhostscript(pdfBytes);
+                    } catch (IOException e) {
+                        log.warn("Ghostscript optimization failed, returning unoptimized PDF", e);
+                        return pdfBytes;
+                    }
+                }
+
+                return pdfBytes;
+            }
+        }
+    }
+
+    private void validateCbrFile(MultipartFile file) {
+        if (file == null || file.isEmpty()) {
+            throw new IllegalArgumentException("File cannot be null or empty");
+        }
+
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            throw new IllegalArgumentException("File must have a name");
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        if (!"cbr".equals(extension) && !"rar".equals(extension)) {
+            throw new IllegalArgumentException("File must be a CBR or RAR archive");
+        }
+    }
+
+    public boolean isCbrFile(MultipartFile file) {
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            return false;
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        return "cbr".equals(extension) || "rar".equals(extension);
+    }
+
+    private boolean isImageFile(String filename) {
+        return RegexPatternUtils.getInstance().getImageFilePattern().matcher(filename).matches();
+    }
+
+    private record ImageEntryData(String name, byte[] data) {}
+
+    private class NaturalOrderComparator implements Comparator<String> {
+        private static String getChunk(String s, int length, int marker) {
+            StringBuilder chunk = new StringBuilder();
+            char c = s.charAt(marker);
+            chunk.append(c);
+            marker++;
+
+            if (isDigit(c)) {
+                while (marker < length && isDigit(s.charAt(marker))) {
+                    chunk.append(s.charAt(marker));
+                    marker++;
+                }
+            } else {
+                while (marker < length && !isDigit(s.charAt(marker))) {
+                    chunk.append(s.charAt(marker));
+                    marker++;
+                }
+            }
+            return chunk.toString();
+        }
+
+        private static boolean isDigit(char ch) {
+            return ch >= '0' && ch <= '9';
+        }
+
+        @Override
+        public int compare(String s1, String s2) {
+            int len1 = s1.length();
+            int len2 = s2.length();
+            int marker1 = 0, marker2 = 0;
+
+            while (marker1 < len1 && marker2 < len2) {
+                String chunk1 = getChunk(s1, len1, marker1);
+                marker1 += chunk1.length();
+
+                String chunk2 = getChunk(s2, len2, marker2);
+                marker2 += chunk2.length();
+
+                int result;
+                if (isDigit(chunk1.charAt(0)) && isDigit(chunk2.charAt(0))) {
+                    int thisNumericValue = Integer.parseInt(chunk1);
+                    int thatNumericValue = Integer.parseInt(chunk2);
+                    result = Integer.compare(thisNumericValue, thatNumericValue);
+                } else {
+                    result = chunk1.compareTo(chunk2);
+                }
+
+                if (result != 0) {
+                    return result;
+                }
+            }
+
+            return Integer.compare(len1, len2);
+        }
+    }
+}

app/common/src/main/java/stirling/software/common/util/CbzUtils.java

@@ -0,0 +1,231 @@
+package stirling.software.common.util;
+
+import java.io.BufferedInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
+import java.util.zip.ZipInputStream;
+
+import org.apache.commons.io.FilenameUtils;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.PDPageContentStream;
+import org.apache.pdfbox.pdmodel.common.PDRectangle;
+import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
+import org.springframework.web.multipart.MultipartFile;
+
+import lombok.experimental.UtilityClass;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.common.service.CustomPDFDocumentFactory;
+
+@Slf4j
+@UtilityClass
+public class CbzUtils {
+
+    public byte[] convertCbzToPdf(
+            MultipartFile cbzFile,
+            CustomPDFDocumentFactory pdfDocumentFactory,
+            TempFileManager tempFileManager)
+            throws IOException {
+        return convertCbzToPdf(cbzFile, pdfDocumentFactory, tempFileManager, false);
+    }
+
+    public byte[] convertCbzToPdf(
+            MultipartFile cbzFile,
+            CustomPDFDocumentFactory pdfDocumentFactory,
+            TempFileManager tempFileManager,
+            boolean optimizeForEbook)
+            throws IOException {
+
+        validateCbzFile(cbzFile);
+
+        try (TempFile tempFile = new TempFile(tempFileManager, ".cbz")) {
+            cbzFile.transferTo(tempFile.getFile());
+
+            // Early ZIP validity check using ZipInputStream (fail fast on non-zip content)
+            try (BufferedInputStream bis =
+                            new BufferedInputStream(
+                                    new java.io.FileInputStream(tempFile.getFile()));
+                    ZipInputStream zis = new ZipInputStream(bis)) {
+                if (zis.getNextEntry() == null) {
+                    throw new IllegalArgumentException("Archive is empty or invalid ZIP");
+                }
+            } catch (IOException e) {
+                throw new IllegalArgumentException("Invalid CBZ/ZIP archive", e);
+            }
+
+            try (PDDocument document = pdfDocumentFactory.createNewDocument();
+                    ZipFile zipFile = new ZipFile(tempFile.getFile())) {
+                Enumeration<? extends ZipEntry> entries = zipFile.entries();
+                List<ImageEntryData> imageEntries = new ArrayList<>();
+                while (entries.hasMoreElements()) {
+                    ZipEntry entry = entries.nextElement();
+                    if (!entry.isDirectory() && isImageFile(entry.getName())) {
+                        try (InputStream is = zipFile.getInputStream(entry)) {
+                            ByteArrayOutputStream baos = new ByteArrayOutputStream();
+                            is.transferTo(baos);
+                            imageEntries.add(
+                                    new ImageEntryData(entry.getName(), baos.toByteArray()));
+                        } catch (IOException e) {
+                            log.warn("Error reading image {}: {}", entry.getName(), e.getMessage());
+                        }
+                    }
+                }
+
+                imageEntries.sort(
+                        Comparator.comparing(ImageEntryData::name, new NaturalOrderComparator()));
+
+                if (imageEntries.isEmpty()) {
+                    throw new IllegalArgumentException("No valid images found in the CBZ file");
+                }
+
+                for (ImageEntryData imageEntry : imageEntries) {
+                    try {
+                        PDImageXObject pdImage =
+                                PDImageXObject.createFromByteArray(
+                                        document, imageEntry.data(), imageEntry.name());
+                        PDPage page =
+                                new PDPage(
+                                        new PDRectangle(pdImage.getWidth(), pdImage.getHeight()));
+                        document.addPage(page);
+                        try (PDPageContentStream contentStream =
+                                new PDPageContentStream(document, page)) {
+                            contentStream.drawImage(pdImage, 0, 0);
+                        }
+                    } catch (IOException e) {
+                        log.warn(
+                                "Error processing image {}: {}", imageEntry.name(), e.getMessage());
+                    }
+                }
+
+                if (document.getNumberOfPages() == 0) {
+                    throw new IllegalArgumentException(
+                            "No images could be processed from the CBZ file");
+                }
+                ByteArrayOutputStream baos = new ByteArrayOutputStream();
+                document.save(baos);
+                byte[] pdfBytes = baos.toByteArray();
+
+                // Apply Ghostscript optimization if requested
+                if (optimizeForEbook) {
+                    try {
+                        return GeneralUtils.optimizePdfWithGhostscript(pdfBytes);
+                    } catch (IOException e) {
+                        log.warn("Ghostscript optimization failed, returning unoptimized PDF", e);
+                        return pdfBytes;
+                    }
+                }
+
+                return pdfBytes;
+            }
+        }
+    }
+
+    private void validateCbzFile(MultipartFile file) {
+        if (file == null || file.isEmpty()) {
+            throw new IllegalArgumentException("File cannot be null or empty");
+        }
+
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            throw new IllegalArgumentException("File must have a name");
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        if (!"cbz".equals(extension) && !"zip".equals(extension)) {
+            throw new IllegalArgumentException("File must be a CBZ or ZIP archive");
+        }
+    }
+
+    public boolean isCbzFile(MultipartFile file) {
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            return false;
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        return "cbz".equals(extension) || "zip".equals(extension);
+    }
+
+    public static boolean isComicBookFile(MultipartFile file) {
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            return false;
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        return "cbz".equals(extension)
+                || "zip".equals(extension)
+                || "cbr".equals(extension)
+                || "rar".equals(extension);
+    }
+
+    private boolean isImageFile(String filename) {
+        return RegexPatternUtils.getInstance().getImageFilePattern().matcher(filename).matches();
+    }
+
+    private record ImageEntryData(String name, byte[] data) {}
+
+    private class NaturalOrderComparator implements Comparator<String> {
+        @Override
+        public int compare(String s1, String s2) {
+            int len1 = s1.length();
+            int len2 = s2.length();
+            int marker1 = 0, marker2 = 0;
+
+            while (marker1 < len1 && marker2 < len2) {
+                String chunk1 = getChunk(s1, len1, marker1);
+                marker1 += chunk1.length();
+
+                String chunk2 = getChunk(s2, len2, marker2);
+                marker2 += chunk2.length();
+
+                int result;
+                if (isDigit(chunk1.charAt(0)) && isDigit(chunk2.charAt(0))) {
+                    int thisNumericValue = Integer.parseInt(chunk1);
+                    int thatNumericValue = Integer.parseInt(chunk2);
+                    result = Integer.compare(thisNumericValue, thatNumericValue);
+                } else {
+                    result = chunk1.compareTo(chunk2);
+                }
+
+                if (result != 0) {
+                    return result;
+                }
+            }
+
+            return Integer.compare(len1, len2);
+        }
+
+        private static String getChunk(String s, int length, int marker) {
+            StringBuilder chunk = new StringBuilder();
+            char c = s.charAt(marker);
+            chunk.append(c);
+            marker++;
+
+            if (isDigit(c)) {
+                while (marker < length && isDigit(s.charAt(marker))) {
+                    chunk.append(s.charAt(marker));
+                    marker++;
+                }
+            } else {
+                while (marker < length && !isDigit(s.charAt(marker))) {
+                    chunk.append(s.charAt(marker));
+                    marker++;
+                }
+            }
+            return chunk.toString();
+        }
+
+        private static boolean isDigit(char ch) {
+            return ch >= '0' && ch <= '9';
+        }
+    }
+}

app/common/src/main/java/stirling/software/common/util/ChecksumUtils.java

@@ -0,0 +1,301 @@
+package stirling.software.common.util;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Base64;
+import java.util.LinkedHashMap;
+import java.util.Locale;
+import java.util.Map;
+import java.util.zip.Adler32;
+import java.util.zip.CRC32;
+import java.util.zip.Checksum;
+
+import lombok.experimental.UtilityClass;
+
+@UtilityClass
+public class ChecksumUtils {
+
+    /** Shared buffer size for streaming I/O. */
+    private static final int BUFFER_SIZE = 8192;
+
+    /** Mask to extract the lower 32 bits of a long value (unsigned int). */
+    private static final long UNSIGNED_32_BIT_MASK = 0xFFFFFFFFL;
+
+    /**
+     * Computes a checksum for the given file using the chosen algorithm and returns a lowercase hex
+     * string.
+     *
+     * <p>For digest algorithms (e.g., SHA-256, SHA-1, MD5), this returns the digest as hex. For
+     * 32-bit {@link Checksum} algorithms ("CRC32", "ADLER32"), this returns an 8-character
+     * lowercase hex string of the unsigned 32-bit value.
+     *
+     * @param path file to read
+     * @param algorithm algorithm name (case-insensitive). Special values: "CRC32", "ADLER32".
+     * @return hex string of the checksum
+     * @throws IOException if the file cannot be read
+     */
+    public static String checksum(Path path, String algorithm) throws IOException {
+        try (InputStream is = Files.newInputStream(path)) {
+            return checksum(is, algorithm);
+        }
+    }
+
+    /**
+     * Computes a checksum for the given stream using the chosen algorithm and returns a lowercase
+     * hex string.
+     *
+     * <p><strong>Note:</strong> This method does <em>not</em> close the provided stream.
+     *
+     * @param is input stream (not closed by this method)
+     * @param algorithm algorithm name (case-insensitive). Special values: "CRC32", "ADLER32".
+     * @return hex string of the checksum
+     * @throws IOException if reading from the stream fails
+     */
+    public static String checksum(InputStream is, String algorithm) throws IOException {
+        switch (algorithm.toUpperCase(Locale.ROOT)) {
+            case "CRC32":
+                return checksumChecksum(is, new CRC32());
+            case "ADLER32":
+                return checksumChecksum(is, new Adler32());
+            default:
+                return toHex(checksumBytes(is, algorithm));
+        }
+    }
+
+    /**
+     * Computes a checksum for the given file using the chosen algorithm and returns a Base64
+     * encoded string.
+     *
+     * <p>For digest algorithms this is the Base64 of the raw digest bytes. For 32-bit checksum
+     * algorithms ("CRC32", "ADLER32"), this is the Base64 of the 4-byte big-endian unsigned value.
+     *
+     * @param path file to read
+     * @param algorithm algorithm name (case-insensitive). Special values: "CRC32", "ADLER32".
+     * @return Base64-encoded checksum bytes
+     * @throws IOException if the file cannot be read
+     */
+    public static String checksumBase64(Path path, String algorithm) throws IOException {
+        try (InputStream is = Files.newInputStream(path)) {
+            return checksumBase64(is, algorithm);
+        }
+    }
+
+    /**
+     * Computes a checksum for the given stream using the chosen algorithm and returns a Base64
+     * encoded string.
+     *
+     * <p><strong>Note:</strong> This method does <em>not</em> close the provided stream.
+     *
+     * @param is input stream (not closed by this method)
+     * @param algorithm algorithm name (case-insensitive). Special values: "CRC32", "ADLER32".
+     * @return Base64-encoded checksum bytes
+     * @throws IOException if reading from the stream fails
+     */
+    public static String checksumBase64(InputStream is, String algorithm) throws IOException {
+        switch (algorithm.toUpperCase(Locale.ROOT)) {
+            case "CRC32":
+                return Base64.getEncoder().encodeToString(checksumChecksumBytes(is, new CRC32()));
+            case "ADLER32":
+                return Base64.getEncoder().encodeToString(checksumChecksumBytes(is, new Adler32()));
+            default:
+                return Base64.getEncoder().encodeToString(checksumBytes(is, algorithm));
+        }
+    }
+
+    /**
+     * Computes multiple checksums for the given file in a single pass over the data.
+     *
+     * <p>Returns a map from algorithm name to lowercase hex string. Order of results follows the
+     * order of the provided {@code algorithms}.
+     *
+     * @param path file to read
+     * @param algorithms algorithm names (case-insensitive). Special: "CRC32", "ADLER32".
+     * @return map of algorithm → hex string
+     * @throws IOException if the file cannot be read
+     */
+    public static Map<String, String> checksums(Path path, String... algorithms)
+            throws IOException {
+        try (InputStream is = Files.newInputStream(path)) {
+            return checksums(is, algorithms);
+        }
+    }
+
+    /**
+     * Computes multiple checksums for the given stream in a single pass over the data.
+     *
+     * <p><strong>Note:</strong> This method does <em>not</em> close the provided stream.
+     *
+     * @param is input stream (not closed by this method)
+     * @param algorithms algorithm names (case-insensitive). Special: "CRC32", "ADLER32".
+     * @return map of algorithm → hex string
+     * @throws IOException if reading from the stream fails
+     */
+    public static Map<String, String> checksums(InputStream is, String... algorithms)
+            throws IOException {
+        // Use LinkedHashMap to preserve the order of requested algorithms in the result.
+        Map<String, MessageDigest> digests = new LinkedHashMap<>();
+        Map<String, Checksum> checksums = new LinkedHashMap<>();
+
+        for (String algorithm : algorithms) {
+            String key = algorithm; // keep original key for output
+            switch (algorithm.toUpperCase(Locale.ROOT)) {
+                case "CRC32":
+                    checksums.put(key, new CRC32());
+                    break;
+                case "ADLER32":
+                    checksums.put(key, new Adler32());
+                    break;
+                default:
+                    try {
+                        // For MessageDigest, pass the original name (case-insensitive per JCA)
+                        digests.put(key, MessageDigest.getInstance(algorithm));
+                    } catch (NoSuchAlgorithmException e) {
+                        throw new IllegalStateException("Unsupported algorithm: " + algorithm, e);
+                    }
+            }
+        }
+
+        byte[] buffer = new byte[BUFFER_SIZE];
+        int read;
+        while ((read = is.read(buffer)) != -1) {
+            for (MessageDigest digest : digests.values()) {
+                digest.update(buffer, 0, read);
+            }
+            for (Checksum cs : checksums.values()) {
+                cs.update(buffer, 0, read);
+            }
+        }
+
+        Map<String, String> results = new LinkedHashMap<>();
+        for (Map.Entry<String, MessageDigest> entry : digests.entrySet()) {
+            results.put(entry.getKey(), toHex(entry.getValue().digest()));
+        }
+        for (Map.Entry<String, Checksum> entry : checksums.entrySet()) {
+            // Keep value as long and mask to ensure unsigned hex formatting.
+            long unsigned32 = entry.getValue().getValue() & UNSIGNED_32_BIT_MASK;
+            results.put(entry.getKey(), String.format("%08x", unsigned32));
+        }
+        return results;
+    }
+
+    /**
+     * Compares the checksum of a file with an expected hex string (case-insensitive).
+     *
+     * @param path file to read
+     * @param algorithm algorithm name (case-insensitive). Special: "CRC32", "ADLER32".
+     * @param expected expected hex string (case-insensitive)
+     * @return {@code true} if they match, otherwise {@code false}
+     * @throws IOException if the file cannot be read
+     */
+    public static boolean matches(Path path, String algorithm, String expected) throws IOException {
+        try (InputStream is = Files.newInputStream(path)) {
+            return matches(is, algorithm, expected);
+        }
+    }
+
+    /**
+     * Compares the checksum of a stream with an expected hex string (case-insensitive).
+     *
+     * <p><strong>Note:</strong> This method does <em>not</em> close the provided stream.
+     *
+     * @param is input stream (not closed by this method)
+     * @param algorithm algorithm name (case-insensitive). Special: "CRC32", "ADLER32".
+     * @param expected expected hex string (case-insensitive)
+     * @return {@code true} if they match, otherwise {@code false}
+     * @throws IOException if reading from the stream fails
+     */
+    public static boolean matches(InputStream is, String algorithm, String expected)
+            throws IOException {
+        return checksum(is, algorithm).equalsIgnoreCase(expected);
+    }
+
+    // ---------- Internal helpers ----------
+
+    /**
+     * Computes a MessageDigest over a stream and returns the raw digest bytes.
+     *
+     * @param is input stream (not closed)
+     * @param algorithm JCA MessageDigest algorithm (e.g., "SHA-256")
+     * @return raw digest bytes
+     * @throws IOException if reading fails
+     * @throws IllegalStateException if the algorithm is unsupported
+     */
+    private static byte[] checksumBytes(InputStream is, String algorithm) throws IOException {
+        try {
+            MessageDigest digest = MessageDigest.getInstance(algorithm);
+            byte[] buffer = new byte[BUFFER_SIZE];
+            int read;
+            while ((read = is.read(buffer)) != -1) {
+                digest.update(buffer, 0, read);
+            }
+            return digest.digest();
+        } catch (NoSuchAlgorithmException e) {
+            // Keep the message explicit to aid debugging
+            throw new IllegalStateException("Unsupported algorithm: " + algorithm, e);
+        }
+    }
+
+    /**
+     * Computes a 32-bit {@link Checksum} over a stream and returns the lowercase 8-char hex of the
+     * unsigned 32-bit value.
+     *
+     * @param is input stream (not closed)
+     * @param checksum checksum implementation (CRC32, Adler32, etc.)
+     * @return 8-character lowercase hex (big-endian representation)
+     * @throws IOException if reading fails
+     */
+    private static String checksumChecksum(InputStream is, Checksum checksum) throws IOException {
+        byte[] buffer = new byte[BUFFER_SIZE];
+        int read;
+        while ((read = is.read(buffer)) != -1) {
+            checksum.update(buffer, 0, read);
+        }
+        // Keep as long and mask to ensure correct unsigned representation.
+        long unsigned32 = checksum.getValue() & UNSIGNED_32_BIT_MASK;
+        return String.format("%08x", unsigned32);
+    }
+
+    /**
+     * Computes a 32-bit {@link Checksum} over a stream and returns the raw 4-byte big-endian
+     * representation of the unsigned 32-bit value.
+     *
+     * <p>Cast to int already truncates to the lower 32 bits; the sign is irrelevant because we
+     * serialize the bit pattern directly into 4 bytes.
+     *
+     * @param is input stream (not closed)
+     * @param checksum checksum implementation (CRC32, Adler32, etc.)
+     * @return 4 bytes (big-endian)
+     * @throws IOException if reading fails
+     */
+    private static byte[] checksumChecksumBytes(InputStream is, Checksum checksum)
+            throws IOException {
+        byte[] buffer = new byte[BUFFER_SIZE];
+        int read;
+        while ((read = is.read(buffer)) != -1) {
+            checksum.update(buffer, 0, read);
+        }
+        // Cast keeps only the lower 32 bits; mask is unnecessary here.
+        int v = (int) checksum.getValue();
+        return ByteBuffer.allocate(4).order(ByteOrder.BIG_ENDIAN).putInt(v).array();
+    }
+
+    /**
+     * Converts bytes to a lowercase hex string.
+     *
+     * @param hash the byte array to convert
+     * @return the lowercase hex string
+     */
+    private static String toHex(byte[] hash) {
+        StringBuilder sb = new StringBuilder(hash.length * 2);
+        for (byte b : hash) {
+            sb.append(String.format("%02x", b));
+        }
+        return sb.toString();
+    }
+}

app/common/src/main/java/stirling/software/common/util/CustomHtmlSanitizer.java

@@ -4,7 +4,6 @@ import org.owasp.html.AttributePolicy;
 import org.owasp.html.HtmlPolicyBuilder;
 import org.owasp.html.PolicyFactory;
 import org.owasp.html.Sanitizers;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
 import stirling.software.common.model.ApplicationProperties;
@@ -16,7 +15,6 @@ public class CustomHtmlSanitizer {
     private final SsrfProtectionService ssrfProtectionService;
     private final ApplicationProperties applicationProperties;
 
-    @Autowired
     public CustomHtmlSanitizer(
             SsrfProtectionService ssrfProtectionService,
             ApplicationProperties applicationProperties) {
@@ -28,7 +26,7 @@ public class CustomHtmlSanitizer {
             new AttributePolicy() {
                 @Override
                 public String apply(String elementName, String attributeName, String value) {
-                    if (value == null || value.trim().isEmpty()) {
+                    if (value.trim().isEmpty()) {
                         return null;
                     }
 

app/common/src/main/java/stirling/software/common/util/EmlParser.java

@@ -6,12 +6,16 @@ import java.io.InputStream;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Method;
 import java.nio.charset.StandardCharsets;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 import java.util.Properties;
 import java.util.regex.Pattern;
 
+import org.springframework.http.MediaType;
+
 import lombok.Data;
 import lombok.experimental.UtilityClass;
 
@@ -25,11 +29,11 @@ public class EmlParser {
     private static volatile boolean mimeUtilityChecked = false;
 
     private static final Pattern MIME_ENCODED_PATTERN =
-            Pattern.compile("=\\?([^?]+)\\?([BbQq])\\?([^?]*)\\?=");
+            RegexPatternUtils.getInstance().getMimeEncodedWordPattern();
 
     private static final String DISPOSITION_ATTACHMENT = "attachment";
-    private static final String TEXT_PLAIN = "text/plain";
-    private static final String TEXT_HTML = "text/html";
+    private static final String TEXT_PLAIN = MediaType.TEXT_PLAIN_VALUE;
+    private static final String TEXT_HTML = MediaType.TEXT_HTML_VALUE;
     private static final String MULTIPART_PREFIX = "multipart/";
 
     private static final String HEADER_CONTENT_TYPE = "content-type:";
@@ -69,12 +73,12 @@ public class EmlParser {
         if (isJakartaMailAvailable()) {
             return extractEmailContentAdvanced(emlBytes, request, customHtmlSanitizer);
         } else {
-            return extractEmailContentBasic(emlBytes, request, customHtmlSanitizer);
+            return extractEmailContentBasic(emlBytes, customHtmlSanitizer);
         }
     }
 
     private static EmailContent extractEmailContentBasic(
-            byte[] emlBytes, EmlToPdfRequest request, CustomHtmlSanitizer customHtmlSanitizer) {
+            byte[] emlBytes, CustomHtmlSanitizer customHtmlSanitizer) {
         String emlContent = new String(emlBytes, StandardCharsets.UTF_8);
         EmailContent content = new EmailContent();
 
@@ -121,7 +125,7 @@ public class EmlParser {
             return extractFromMimeMessage(message, request, customHtmlSanitizer);
 
         } catch (ReflectiveOperationException e) {
-            return extractEmailContentBasic(emlBytes, request, customHtmlSanitizer);
+            return extractEmailContentBasic(emlBytes, customHtmlSanitizer);
         }
     }
 
@@ -143,7 +147,11 @@ public class EmlParser {
             extractRecipients(message, messageClass, content);
 
             Method getSentDate = messageClass.getMethod("getSentDate");
-            content.setDate((Date) getSentDate.invoke(message));
+            Date legacyDate = (Date) getSentDate.invoke(message);
+            if (legacyDate != null) {
+                content.setDate(
+                        ZonedDateTime.ofInstant(legacyDate.toInstant(), ZoneId.systemDefault()));
+            }
 
             Method getContent = messageClass.getMethod("getContent");
             Object messageContent = getContent.invoke(message);
@@ -349,7 +357,11 @@ public class EmlParser {
                     for (String contentIdHeader : contentIdHeaders) {
                         if (contentIdHeader != null && !contentIdHeader.trim().isEmpty()) {
                             attachment.setEmbedded(true);
-                            String contentId = contentIdHeader.trim().replaceAll("[<>]", "");
+                            String contentId =
+                                    RegexPatternUtils.getInstance()
+                                            .getAngleBracketsPattern()
+                                            .matcher(contentIdHeader.trim())
+                                            .replaceAll("");
                             attachment.setContentId(contentId);
                             break;
                         }
@@ -406,7 +418,8 @@ public class EmlParser {
 
     private static String extractBasicHeader(String emlContent, String headerName) {
         try {
-            String[] lines = emlContent.split("\r?\n");
+            String[] lines =
+                    RegexPatternUtils.getInstance().getNewlineSplitPattern().split(emlContent);
             for (int i = 0; i < lines.length; i++) {
                 String line = lines[i];
                 if (line.toLowerCase().startsWith(headerName.toLowerCase())) {
@@ -477,7 +490,10 @@ public class EmlParser {
     }
 
     private static int findPartEnd(String content, int start) {
-        String[] lines = content.substring(start).split("\r?\n");
+        String[] lines =
+                RegexPatternUtils.getInstance()
+                        .getNewlineSplitPattern()
+                        .split(content.substring(start));
         StringBuilder result = new StringBuilder();
 
         for (String line : lines) {
@@ -491,7 +507,8 @@ public class EmlParser {
     private static List<EmailAttachment> extractAttachmentsBasic(String emlContent) {
         List<EmailAttachment> attachments = new ArrayList<>();
         try {
-            String[] lines = emlContent.split("\r?\n");
+            String[] lines =
+                    RegexPatternUtils.getInstance().getNewlineSplitPattern().split(emlContent);
             boolean inHeaders = true;
             String currentContentType = "";
             String currentDisposition = "";
@@ -554,7 +571,11 @@ public class EmlParser {
             if (filenameStarEnd == -1) filenameStarEnd = disposition.length();
             String extendedFilename =
                     disposition.substring(filenameStarStart, filenameStarEnd).trim();
-            extendedFilename = extendedFilename.replaceAll("^\"|\"$", "");
+            extendedFilename =
+                    RegexPatternUtils.getInstance()
+                            .getQuotesRemovalPattern()
+                            .matcher(extendedFilename)
+                            .replaceAll("");
 
             if (extendedFilename.contains("'")) {
                 String[] parts = extendedFilename.split("'", 3);
@@ -569,7 +590,11 @@ public class EmlParser {
         int filenameEnd = disposition.indexOf(";", filenameStart);
         if (filenameEnd == -1) filenameEnd = disposition.length();
         String filename = disposition.substring(filenameStart, filenameEnd).trim();
-        filename = filename.replaceAll("^\"|\"$", "");
+        filename =
+                RegexPatternUtils.getInstance()
+                        .getQuotesRemovalPattern()
+                        .matcher(filename)
+                        .replaceAll("");
         return safeMimeDecode(filename);
     }
 
@@ -614,7 +639,7 @@ public class EmlParser {
         private String to;
         private String cc;
         private String bcc;
-        private Date date;
+        private ZonedDateTime date;
         private String dateString; // For basic parsing fallback
         private String htmlBody;
         private String textBody;
@@ -622,11 +647,23 @@ public class EmlParser {
         private List<EmailAttachment> attachments = new ArrayList<>();
 
         public void setHtmlBody(String htmlBody) {
-            this.htmlBody = htmlBody != null ? htmlBody.replaceAll("\r", "") : null;
+            this.htmlBody =
+                    htmlBody != null
+                            ? RegexPatternUtils.getInstance()
+                                    .getCarriageReturnPattern()
+                                    .matcher(htmlBody)
+                                    .replaceAll("")
+                            : null;
         }
 
         public void setTextBody(String textBody) {
-            this.textBody = textBody != null ? textBody.replaceAll("\r", "") : null;
+            this.textBody =
+                    textBody != null
+                            ? RegexPatternUtils.getInstance()
+                                    .getCarriageReturnPattern()
+                                    .matcher(textBody)
+                                    .replaceAll("")
+                            : null;
         }
     }
 

app/common/src/main/java/stirling/software/common/util/EmlProcessingUtils.java

@@ -8,6 +8,8 @@ import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import org.springframework.http.MediaType;
+
 import lombok.experimental.UtilityClass;
 
 import stirling.software.common.model.api.converters.EmlToPdfRequest;
@@ -33,10 +35,10 @@ public class EmlProcessingUtils {
     // MIME type detection
     private static final Map<String, String> EXTENSION_TO_MIME_TYPE =
             Map.of(
-                    ".png", "image/png",
-                    ".jpg", "image/jpeg",
-                    ".jpeg", "image/jpeg",
-                    ".gif", "image/gif",
+                    ".png", MediaType.IMAGE_PNG_VALUE,
+                    ".jpg", MediaType.IMAGE_JPEG_VALUE,
+                    ".jpeg", MediaType.IMAGE_JPEG_VALUE,
+                    ".gif", MediaType.IMAGE_GIF_VALUE,
                     ".bmp", "image/bmp",
                     ".webp", "image/webp",
                     ".svg", "image/svg+xml",
@@ -81,8 +83,8 @@ public class EmlProcessingUtils {
                             || lowerContent.contains("bcc:");
             boolean hasMimeStructure =
                     lowerContent.contains("multipart/")
-                            || lowerContent.contains("text/plain")
-                            || lowerContent.contains("text/html")
+                            || lowerContent.contains(MediaType.TEXT_PLAIN_VALUE)
+                            || lowerContent.contains(MediaType.TEXT_HTML_VALUE)
                             || lowerContent.contains("boundary=");
 
             int headerCount = 0;
@@ -197,8 +199,16 @@ public class EmlProcessingUtils {
         String processed =
                 customHtmlSanitizer != null ? customHtmlSanitizer.sanitize(htmlBody) : htmlBody;
 
-        processed = processed.replaceAll("(?i)\\s*position\\s*:\\s*fixed[^;]*;?", "");
-        processed = processed.replaceAll("(?i)\\s*position\\s*:\\s*absolute[^;]*;?", "");
+        processed =
+                RegexPatternUtils.getInstance()
+                        .getFixedPositionCssPattern()
+                        .matcher(processed)
+                        .replaceAll("");
+        processed =
+                RegexPatternUtils.getInstance()
+                        .getAbsolutePositionCssPattern()
+                        .matcher(processed)
+                        .replaceAll("");
 
         if (emailContent != null && !emailContent.getAttachments().isEmpty()) {
             processed = PdfAttachmentHandler.processInlineImages(processed, emailContent);
@@ -220,14 +230,18 @@ public class EmlProcessingUtils {
         html = html.replace("\n", "<br>\n");
 
         html =
-                html.replaceAll(
-                        "(https?://[\\w\\-._~:/?#\\[\\]@!$&'()*+,;=%]+)",
-                        "<a href=\"$1\" style=\"color: #1a73e8; text-decoration: underline;\">$1</a>");
+                RegexPatternUtils.getInstance()
+                        .getUrlLinkPattern()
+                        .matcher(html)
+                        .replaceAll(
+                                "<a href=\"$1\" style=\"color: #1a73e8; text-decoration: underline;\">$1</a>");
 
         html =
-                html.replaceAll(
-                        "([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,63})",
-                        "<a href=\"mailto:$1\" style=\"color: #1a73e8; text-decoration: underline;\">$1</a>");
+                RegexPatternUtils.getInstance()
+                        .getEmailLinkPattern()
+                        .matcher(html)
+                        .replaceAll(
+                                "<a href=\"mailto:$1\" style=\"color: #1a73e8; text-decoration: underline;\">$1</a>");
 
         return html;
     }
@@ -464,7 +478,7 @@ public class EmlProcessingUtils {
             }
         }
 
-        return "image/png";
+        return MediaType.IMAGE_PNG_VALUE; // Default MIME type
     }
 
     public static String decodeUrlEncoded(String encoded) {
@@ -488,9 +502,13 @@ public class EmlProcessingUtils {
             Matcher concatenatedMatcher = concatenatedPattern.matcher(encodedText);
             String processedText =
                     concatenatedMatcher.replaceAll(
-                            match -> match.group().replaceAll("\\s+(?==\\?)", ""));
+                            match ->
+                                    RegexPatternUtils.getInstance()
+                                            .getMimeHeaderWhitespacePattern()
+                                            .matcher(match.group())
+                                            .replaceAll(""));
 
-            Pattern mimePattern = Pattern.compile("=\\?([^?]+)\\?([BbQq])\\?([^?]*)\\?=");
+            Pattern mimePattern = RegexPatternUtils.getInstance().getMimeEncodedWordPattern();
             Matcher matcher = mimePattern.matcher(processedText);
             int lastEnd = 0;
 
@@ -505,7 +523,11 @@ public class EmlProcessingUtils {
                     String decodedValue =
                             switch (encoding) {
                                 case "B" -> {
-                                    String cleanBase64 = encodedValue.replaceAll("\\s", "");
+                                    String cleanBase64 =
+                                            RegexPatternUtils.getInstance()
+                                                    .getWhitespacePattern()
+                                                    .matcher(encodedValue)
+                                                    .replaceAll("");
                                     byte[] decodedBytes = Base64.getDecoder().decode(cleanBase64);
                                     Charset targetCharset;
                                     try {
@@ -594,8 +616,16 @@ public class EmlProcessingUtils {
     }
 
     public static String simplifyHtmlContent(String htmlContent) {
-        String simplified = htmlContent.replaceAll("(?i)<script[^>]*>.*?</script>", "");
-        simplified = simplified.replaceAll("(?i)<style[^>]*>.*?</style>", "");
+        String simplified =
+                RegexPatternUtils.getInstance()
+                        .getScriptTagPattern()
+                        .matcher(htmlContent)
+                        .replaceAll("");
+        simplified =
+                RegexPatternUtils.getInstance()
+                        .getStyleTagPattern()
+                        .matcher(simplified)
+                        .replaceAll("");
         return simplified;
     }
 }

app/common/src/main/java/stirling/software/common/util/ExceptionUtils.java

@@ -324,4 +324,63 @@ public class ExceptionUtils {
         return createIllegalArgumentException(
                 "error.argumentRequired", "{0} must not be null", argumentName);
     }
+
+    /**
+     * Create a RuntimeException for memory/image size errors when rendering PDF images with DPI.
+     * Handles OutOfMemoryError and related conditions (e.g., NegativeArraySizeException) that
+     * result from images exceeding Java's array/memory limits.
+     *
+     * @param pageNumber the page number that caused the error
+     * @param dpi the DPI value used
+     * @param cause the original error/exception (e.g., OutOfMemoryError,
+     *     NegativeArraySizeException)
+     * @return RuntimeException with user-friendly message
+     */
+    public static RuntimeException createOutOfMemoryDpiException(
+            int pageNumber, int dpi, Throwable cause) {
+        String message =
+                MessageFormat.format(
+                        "Out of memory or image-too-large error while rendering PDF page {0} at {1} DPI. "
+                                + "This can occur when the resulting image exceeds Java's array/memory limits (e.g., NegativeArraySizeException). "
+                                + "Please use a lower DPI value (recommended: 150 or less) or process the document in smaller chunks.",
+                        pageNumber, dpi);
+        return new RuntimeException(message, cause);
+    }
+
+    /**
+     * Create a RuntimeException for OutOfMemoryError when rendering PDF images with DPI.
+     *
+     * @param pageNumber the page number that caused the error
+     * @param dpi the DPI value used
+     * @param cause the original OutOfMemoryError
+     * @return RuntimeException with user-friendly message
+     */
+    public static RuntimeException createOutOfMemoryDpiException(
+            int pageNumber, int dpi, OutOfMemoryError cause) {
+        return createOutOfMemoryDpiException(pageNumber, dpi, (Throwable) cause);
+    }
+
+    /**
+     * Create a RuntimeException for memory/image size errors when rendering PDF images with DPI.
+     * Handles OutOfMemoryError and related conditions (e.g., NegativeArraySizeException) that
+     * result from images exceeding Java's array/memory limits.
+     *
+     * @param dpi the DPI value used
+     * @param cause the original error/exception (e.g., OutOfMemoryError,
+     *     NegativeArraySizeException)
+     * @return RuntimeException with user-friendly message
+     */
+    public static RuntimeException createOutOfMemoryDpiException(int dpi, Throwable cause) {
+        String message =
+                MessageFormat.format(
+                        "Out of memory or image-too-large error while rendering PDF at {0} DPI. "
+                                + "This can occur when the resulting image exceeds Java's array/memory limits (e.g., NegativeArraySizeException). "
+                                + "Please use a lower DPI value (recommended: 150 or less) or process the document in smaller chunks.",
+                        dpi);
+        return new RuntimeException(message, cause);
+    }
+
+    public static RuntimeException createOutOfMemoryDpiException(int dpi, OutOfMemoryError cause) {
+        return createOutOfMemoryDpiException(dpi, (Throwable) cause);
+    }
 }

app/common/src/main/java/stirling/software/common/util/FileToPdf.java

@@ -1,6 +1,9 @@
 package stirling.software.common.util;
 
-import java.io.*;
+import java.io.ByteArrayInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
@@ -124,20 +127,21 @@ public class FileToPdf {
     private static void zipDirectory(Path sourceDir, Path zipFilePath) throws IOException {
         try (ZipOutputStream zos =
                 new ZipOutputStream(new FileOutputStream(zipFilePath.toFile()))) {
-            Files.walk(sourceDir)
-                    .filter(path -> !Files.isDirectory(path))
-                    .forEach(
-                            path -> {
-                                ZipEntry zipEntry =
-                                        new ZipEntry(sourceDir.relativize(path).toString());
-                                try {
-                                    zos.putNextEntry(zipEntry);
-                                    Files.copy(path, zos);
-                                    zos.closeEntry();
-                                } catch (IOException e) {
-                                    throw new UncheckedIOException(e);
-                                }
-                            });
+            try (Stream<Path> walk = Files.walk(sourceDir)) {
+                walk.filter(path -> !Files.isDirectory(path))
+                        .forEach(
+                                path -> {
+                                    ZipEntry zipEntry =
+                                            new ZipEntry(sourceDir.relativize(path).toString());
+                                    try {
+                                        zos.putNextEntry(zipEntry);
+                                        Files.copy(path, zos);
+                                        zos.closeEntry();
+                                    } catch (IOException e) {
+                                        throw new UncheckedIOException(e);
+                                    }
+                                });
+            }
         }
     }
 
@@ -204,15 +208,27 @@ public class FileToPdf {
             return "";
         }
         // Remove any drive letters (e.g., "C:\") and leading forward/backslashes
-        entryName = entryName.replaceAll("^[a-zA-Z]:[\\\\/]+", "");
-        entryName = entryName.replaceAll("^[\\\\/]+", "");
+        entryName =
+                RegexPatternUtils.getInstance()
+                        .getDriveLetterPattern()
+                        .matcher(entryName)
+                        .replaceAll("");
+        entryName =
+                RegexPatternUtils.getInstance()
+                        .getLeadingSlashesPattern()
+                        .matcher(entryName)
+                        .replaceAll("");
 
         // Recursively remove path traversal sequences
         while (entryName.contains("../") || entryName.contains("..\\")) {
             entryName = entryName.replace("../", "").replace("..\\", "");
         }
         // Normalize all backslashes to forward slashes
-        entryName = entryName.replaceAll("\\\\", "/");
+        entryName =
+                RegexPatternUtils.getInstance()
+                        .getBackslashPattern()
+                        .matcher(entryName)
+                        .replaceAll("/");
         return entryName;
     }
 }

app/common/src/main/java/stirling/software/common/util/FormUtils.java

@@ -0,0 +1,658 @@
+package stirling.software.common.util;
+
+import java.io.IOException;
+import java.lang.reflect.Method;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.pdfbox.cos.COSName;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDDocumentCatalog;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.PDResources;
+import org.apache.pdfbox.pdmodel.common.PDRectangle;
+import org.apache.pdfbox.pdmodel.font.PDType1Font;
+import org.apache.pdfbox.pdmodel.font.Standard14Fonts;
+import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotation;
+import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotationWidget;
+import org.apache.pdfbox.pdmodel.interactive.form.*;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public final class FormUtils {
+
+    private FormUtils() {}
+
+    public static boolean hasAnyRotatedPage(PDDocument document) {
+        try {
+            for (PDPage page : document.getPages()) {
+                int rot = page.getRotation();
+                int norm = ((rot % 360) + 360) % 360;
+                if (norm != 0) {
+                    return true;
+                }
+            }
+        } catch (Exception e) {
+            log.warn("Failed to inspect page rotations: {}", e.getMessage(), e);
+        }
+        return false;
+    }
+
+    public static void copyAndTransformFormFields(
+            PDDocument sourceDocument,
+            PDDocument newDocument,
+            int totalPages,
+            int pagesPerSheet,
+            int cols,
+            int rows,
+            float cellWidth,
+            float cellHeight)
+            throws IOException {
+
+        PDDocumentCatalog sourceCatalog = sourceDocument.getDocumentCatalog();
+        PDAcroForm sourceAcroForm = sourceCatalog.getAcroForm();
+
+        if (sourceAcroForm == null || sourceAcroForm.getFields().isEmpty()) {
+            return;
+        }
+
+        PDDocumentCatalog newCatalog = newDocument.getDocumentCatalog();
+        PDAcroForm newAcroForm = new PDAcroForm(newDocument);
+        newCatalog.setAcroForm(newAcroForm);
+
+        PDResources dr = new PDResources();
+        PDType1Font helvetica = new PDType1Font(Standard14Fonts.FontName.HELVETICA);
+        PDType1Font zapfDingbats = new PDType1Font(Standard14Fonts.FontName.ZAPF_DINGBATS);
+        dr.put(COSName.getPDFName("Helv"), helvetica);
+        dr.put(COSName.getPDFName("ZaDb"), zapfDingbats);
+        newAcroForm.setDefaultResources(dr);
+        newAcroForm.setDefaultAppearance("/Helv 12 Tf 0 g");
+
+        // Do not mutate the source AcroForm; skip bad widgets during copy
+        newAcroForm.setNeedAppearances(true);
+
+        Map<String, Integer> fieldNameCounters = new HashMap<>();
+
+        // Build widget -> field map once for efficient lookups
+        Map<PDAnnotationWidget, PDField> widgetFieldMap = buildWidgetFieldMap(sourceAcroForm);
+
+        for (int pageIndex = 0; pageIndex < totalPages; pageIndex++) {
+            PDPage sourcePage = sourceDocument.getPage(pageIndex);
+            List<PDAnnotation> annotations = sourcePage.getAnnotations();
+
+            if (annotations.isEmpty()) {
+                continue;
+            }
+
+            int destinationPageIndex = pageIndex / pagesPerSheet;
+            int adjustedPageIndex = pageIndex % pagesPerSheet;
+            int rowIndex = adjustedPageIndex / cols;
+            int colIndex = adjustedPageIndex % cols;
+
+            if (destinationPageIndex >= newDocument.getNumberOfPages()) {
+                continue;
+            }
+
+            PDPage destinationPage = newDocument.getPage(destinationPageIndex);
+            PDRectangle sourceRect = sourcePage.getMediaBox();
+
+            float scaleWidth = cellWidth / sourceRect.getWidth();
+            float scaleHeight = cellHeight / sourceRect.getHeight();
+            float scale = Math.min(scaleWidth, scaleHeight);
+
+            float x = colIndex * cellWidth + (cellWidth - sourceRect.getWidth() * scale) / 2;
+            float y =
+                    destinationPage.getMediaBox().getHeight()
+                            - ((rowIndex + 1) * cellHeight
+                                    - (cellHeight - sourceRect.getHeight() * scale) / 2);
+
+            copyBasicFormFields(
+                    sourceAcroForm,
+                    newAcroForm,
+                    sourcePage,
+                    destinationPage,
+                    x,
+                    y,
+                    scale,
+                    pageIndex,
+                    fieldNameCounters,
+                    widgetFieldMap);
+        }
+
+        // Refresh appearances to ensure widgets render correctly across viewers
+        try {
+            // Use reflection to avoid compile-time dependency on PDFBox version
+            Method m = newAcroForm.getClass().getMethod("refreshAppearances");
+            m.invoke(newAcroForm);
+        } catch (NoSuchMethodException nsme) {
+            log.warn(
+                    "AcroForm.refreshAppearances() not available in this PDFBox version; relying on NeedAppearances.");
+        } catch (Throwable t) {
+            log.warn("Failed to refresh field appearances via AcroForm: {}", t.getMessage(), t);
+        }
+    }
+
+    private static void copyBasicFormFields(
+            PDAcroForm sourceAcroForm,
+            PDAcroForm newAcroForm,
+            PDPage sourcePage,
+            PDPage destinationPage,
+            float offsetX,
+            float offsetY,
+            float scale,
+            int pageIndex,
+            Map<String, Integer> fieldNameCounters,
+            Map<PDAnnotationWidget, PDField> widgetFieldMap) {
+
+        try {
+            List<PDAnnotation> sourceAnnotations = sourcePage.getAnnotations();
+            List<PDAnnotation> destinationAnnotations = destinationPage.getAnnotations();
+
+            for (PDAnnotation annotation : sourceAnnotations) {
+                if (annotation instanceof PDAnnotationWidget widgetAnnotation) {
+                    if (widgetAnnotation.getRectangle() == null) {
+                        continue;
+                    }
+                    PDField sourceField =
+                            widgetFieldMap != null ? widgetFieldMap.get(widgetAnnotation) : null;
+                    if (sourceField == null) {
+                        continue; // skip widgets without a matching field
+                    }
+                    if (sourceField instanceof PDTextField pdtextfield) {
+                        createSimpleTextField(
+                                newAcroForm,
+                                destinationPage,
+                                destinationAnnotations,
+                                pdtextfield,
+                                widgetAnnotation,
+                                offsetX,
+                                offsetY,
+                                scale,
+                                pageIndex,
+                                fieldNameCounters);
+                    } else if (sourceField instanceof PDCheckBox pdCheckBox) {
+                        createSimpleCheckBoxField(
+                                newAcroForm,
+                                destinationPage,
+                                destinationAnnotations,
+                                pdCheckBox,
+                                widgetAnnotation,
+                                offsetX,
+                                offsetY,
+                                scale,
+                                pageIndex,
+                                fieldNameCounters);
+                    } else if (sourceField instanceof PDRadioButton pdRadioButton) {
+                        createSimpleRadioButtonField(
+                                newAcroForm,
+                                destinationPage,
+                                destinationAnnotations,
+                                pdRadioButton,
+                                widgetAnnotation,
+                                offsetX,
+                                offsetY,
+                                scale,
+                                pageIndex,
+                                fieldNameCounters);
+                    } else if (sourceField instanceof PDComboBox pdComboBox) {
+                        createSimpleComboBoxField(
+                                newAcroForm,
+                                destinationPage,
+                                destinationAnnotations,
+                                pdComboBox,
+                                widgetAnnotation,
+                                offsetX,
+                                offsetY,
+                                scale,
+                                pageIndex,
+                                fieldNameCounters);
+                    } else if (sourceField instanceof PDListBox pdlistbox) {
+                        createSimpleListBoxField(
+                                newAcroForm,
+                                destinationPage,
+                                destinationAnnotations,
+                                pdlistbox,
+                                widgetAnnotation,
+                                offsetX,
+                                offsetY,
+                                scale,
+                                pageIndex,
+                                fieldNameCounters);
+                    } else if (sourceField instanceof PDSignatureField pdSignatureField) {
+                        createSimpleSignatureField(
+                                newAcroForm,
+                                destinationPage,
+                                destinationAnnotations,
+                                pdSignatureField,
+                                widgetAnnotation,
+                                offsetX,
+                                offsetY,
+                                scale,
+                                pageIndex,
+                                fieldNameCounters);
+                    } else if (sourceField instanceof PDPushButton pdPushButton) {
+                        createSimplePushButtonField(
+                                newAcroForm,
+                                destinationPage,
+                                destinationAnnotations,
+                                pdPushButton,
+                                widgetAnnotation,
+                                offsetX,
+                                offsetY,
+                                scale,
+                                pageIndex,
+                                fieldNameCounters);
+                    }
+                }
+            }
+        } catch (Exception e) {
+            log.warn(
+                    "Failed to copy basic form fields for page {}: {}",
+                    pageIndex,
+                    e.getMessage(),
+                    e);
+        }
+    }
+
+    private static void createSimpleTextField(
+            PDAcroForm newAcroForm,
+            PDPage destinationPage,
+            List<PDAnnotation> destinationAnnotations,
+            PDTextField sourceField,
+            PDAnnotationWidget sourceWidget,
+            float offsetX,
+            float offsetY,
+            float scale,
+            int pageIndex,
+            Map<String, Integer> fieldNameCounters) {
+
+        try {
+            PDTextField newTextField = new PDTextField(newAcroForm);
+            newTextField.setDefaultAppearance("/Helv 12 Tf 0 g");
+
+            boolean initialized =
+                    initializeFieldWithWidget(
+                            newAcroForm,
+                            destinationPage,
+                            destinationAnnotations,
+                            newTextField,
+                            sourceField.getPartialName(),
+                            "textField",
+                            sourceWidget,
+                            offsetX,
+                            offsetY,
+                            scale,
+                            pageIndex,
+                            fieldNameCounters);
+
+            if (!initialized) {
+                return;
+            }
+
+            if (sourceField.getValueAsString() != null) {
+                newTextField.setValue(sourceField.getValueAsString());
+            }
+
+        } catch (Exception e) {
+            log.warn(
+                    "Failed to create text field '{}': {}",
+                    sourceField.getPartialName(),
+                    e.getMessage(),
+                    e);
+        }
+    }
+
+    private static void createSimpleCheckBoxField(
+            PDAcroForm newAcroForm,
+            PDPage destinationPage,
+            List<PDAnnotation> destinationAnnotations,
+            PDCheckBox sourceField,
+            PDAnnotationWidget sourceWidget,
+            float offsetX,
+            float offsetY,
+            float scale,
+            int pageIndex,
+            Map<String, Integer> fieldNameCounters) {
+
+        try {
+            PDCheckBox newCheckBox = new PDCheckBox(newAcroForm);
+
+            boolean initialized =
+                    initializeFieldWithWidget(
+                            newAcroForm,
+                            destinationPage,
+                            destinationAnnotations,
+                            newCheckBox,
+                            sourceField.getPartialName(),
+                            "checkBox",
+                            sourceWidget,
+                            offsetX,
+                            offsetY,
+                            scale,
+                            pageIndex,
+                            fieldNameCounters);
+
+            if (!initialized) {
+                return;
+            }
+
+            if (sourceField.isChecked()) {
+                newCheckBox.check();
+            } else {
+                newCheckBox.unCheck();
+            }
+
+        } catch (Exception e) {
+            log.warn(
+                    "Failed to create checkbox field '{}': {}",
+                    sourceField.getPartialName(),
+                    e.getMessage(),
+                    e);
+        }
+    }
+
+    private static void createSimpleRadioButtonField(
+            PDAcroForm newAcroForm,
+            PDPage destinationPage,
+            List<PDAnnotation> destinationAnnotations,
+            PDRadioButton sourceField,
+            PDAnnotationWidget sourceWidget,
+            float offsetX,
+            float offsetY,
+            float scale,
+            int pageIndex,
+            Map<String, Integer> fieldNameCounters) {
+
+        try {
+            PDRadioButton newRadioButton = new PDRadioButton(newAcroForm);
+
+            boolean initialized =
+                    initializeFieldWithWidget(
+                            newAcroForm,
+                            destinationPage,
+                            destinationAnnotations,
+                            newRadioButton,
+                            sourceField.getPartialName(),
+                            "radioButton",
+                            sourceWidget,
+                            offsetX,
+                            offsetY,
+                            scale,
+                            pageIndex,
+                            fieldNameCounters);
+
+            if (!initialized) {
+                return;
+            }
+
+            if (sourceField.getExportValues() != null) {
+                newRadioButton.setExportValues(sourceField.getExportValues());
+            }
+            if (sourceField.getValue() != null) {
+                newRadioButton.setValue(sourceField.getValue());
+            }
+        } catch (Exception e) {
+            log.warn(
+                    "Failed to create radio button field '{}': {}",
+                    sourceField.getPartialName(),
+                    e.getMessage(),
+                    e);
+        }
+    }
+
+    private static void createSimpleComboBoxField(
+            PDAcroForm newAcroForm,
+            PDPage destinationPage,
+            List<PDAnnotation> destinationAnnotations,
+            PDComboBox sourceField,
+            PDAnnotationWidget sourceWidget,
+            float offsetX,
+            float offsetY,
+            float scale,
+            int pageIndex,
+            Map<String, Integer> fieldNameCounters) {
+
+        try {
+            PDComboBox newComboBox = new PDComboBox(newAcroForm);
+
+            boolean initialized =
+                    initializeFieldWithWidget(
+                            newAcroForm,
+                            destinationPage,
+                            destinationAnnotations,
+                            newComboBox,
+                            sourceField.getPartialName(),
+                            "comboBox",
+                            sourceWidget,
+                            offsetX,
+                            offsetY,
+                            scale,
+                            pageIndex,
+                            fieldNameCounters);
+
+            if (!initialized) {
+                return;
+            }
+
+            if (sourceField.getOptions() != null) {
+                newComboBox.setOptions(sourceField.getOptions());
+            }
+            if (sourceField.getValue() != null && !sourceField.getValue().isEmpty()) {
+                newComboBox.setValue(sourceField.getValue());
+            }
+        } catch (Exception e) {
+            log.warn(
+                    "Failed to create combo box field '{}': {}",
+                    sourceField.getPartialName(),
+                    e.getMessage(),
+                    e);
+        }
+    }
+
+    private static void createSimpleListBoxField(
+            PDAcroForm newAcroForm,
+            PDPage destinationPage,
+            List<PDAnnotation> destinationAnnotations,
+            PDListBox sourceField,
+            PDAnnotationWidget sourceWidget,
+            float offsetX,
+            float offsetY,
+            float scale,
+            int pageIndex,
+            Map<String, Integer> fieldNameCounters) {
+
+        try {
+            PDListBox newListBox = new PDListBox(newAcroForm);
+
+            boolean initialized =
+                    initializeFieldWithWidget(
+                            newAcroForm,
+                            destinationPage,
+                            destinationAnnotations,
+                            newListBox,
+                            sourceField.getPartialName(),
+                            "listBox",
+                            sourceWidget,
+                            offsetX,
+                            offsetY,
+                            scale,
+                            pageIndex,
+                            fieldNameCounters);
+
+            if (!initialized) {
+                return;
+            }
+
+            if (sourceField.getOptions() != null) {
+                newListBox.setOptions(sourceField.getOptions());
+            }
+            if (sourceField.getValue() != null && !sourceField.getValue().isEmpty()) {
+                newListBox.setValue(sourceField.getValue());
+            }
+        } catch (Exception e) {
+            log.warn(
+                    "Failed to create list box field '{}': {}",
+                    sourceField.getPartialName(),
+                    e.getMessage(),
+                    e);
+        }
+    }
+
+    private static void createSimpleSignatureField(
+            PDAcroForm newAcroForm,
+            PDPage destinationPage,
+            List<PDAnnotation> destinationAnnotations,
+            PDSignatureField sourceField,
+            PDAnnotationWidget sourceWidget,
+            float offsetX,
+            float offsetY,
+            float scale,
+            int pageIndex,
+            Map<String, Integer> fieldNameCounters) {
+
+        try {
+            PDSignatureField newSignatureField = new PDSignatureField(newAcroForm);
+
+            boolean initialized =
+                    initializeFieldWithWidget(
+                            newAcroForm,
+                            destinationPage,
+                            destinationAnnotations,
+                            newSignatureField,
+                            sourceField.getPartialName(),
+                            "signature",
+                            sourceWidget,
+                            offsetX,
+                            offsetY,
+                            scale,
+                            pageIndex,
+                            fieldNameCounters);
+
+            if (!initialized) {
+                return;
+            }
+        } catch (Exception e) {
+            log.warn(
+                    "Failed to create signature field '{}': {}",
+                    sourceField.getPartialName(),
+                    e.getMessage(),
+                    e);
+        }
+    }
+
+    private static void createSimplePushButtonField(
+            PDAcroForm newAcroForm,
+            PDPage destinationPage,
+            List<PDAnnotation> destinationAnnotations,
+            PDPushButton sourceField,
+            PDAnnotationWidget sourceWidget,
+            float offsetX,
+            float offsetY,
+            float scale,
+            int pageIndex,
+            Map<String, Integer> fieldNameCounters) {
+
+        try {
+            PDPushButton newPushButton = new PDPushButton(newAcroForm);
+
+            boolean initialized =
+                    initializeFieldWithWidget(
+                            newAcroForm,
+                            destinationPage,
+                            destinationAnnotations,
+                            newPushButton,
+                            sourceField.getPartialName(),
+                            "pushButton",
+                            sourceWidget,
+                            offsetX,
+                            offsetY,
+                            scale,
+                            pageIndex,
+                            fieldNameCounters);
+
+        } catch (Exception e) {
+            log.warn(
+                    "Failed to create push button field '{}': {}",
+                    sourceField.getPartialName(),
+                    e.getMessage(),
+                    e);
+        }
+    }
+
+    private static <T extends PDTerminalField> boolean initializeFieldWithWidget(
+            PDAcroForm newAcroForm,
+            PDPage destinationPage,
+            List<PDAnnotation> destinationAnnotations,
+            T newField,
+            String originalName,
+            String fallbackName,
+            PDAnnotationWidget sourceWidget,
+            float offsetX,
+            float offsetY,
+            float scale,
+            int pageIndex,
+            Map<String, Integer> fieldNameCounters) {
+
+        String baseName = (originalName != null) ? originalName : fallbackName;
+        String newFieldName = generateUniqueFieldName(baseName, pageIndex, fieldNameCounters);
+        newField.setPartialName(newFieldName);
+
+        PDAnnotationWidget newWidget = new PDAnnotationWidget();
+        PDRectangle sourceRect = sourceWidget.getRectangle();
+        if (sourceRect == null) {
+            return false;
+        }
+
+        float newX = (sourceRect.getLowerLeftX() * scale) + offsetX;
+        float newY = (sourceRect.getLowerLeftY() * scale) + offsetY;
+        float newWidth = sourceRect.getWidth() * scale;
+        float newHeight = sourceRect.getHeight() * scale;
+        newWidget.setRectangle(new PDRectangle(newX, newY, newWidth, newHeight));
+        newWidget.setPage(destinationPage);
+
+        newField.getWidgets().add(newWidget);
+        newWidget.setParent(newField);
+        newAcroForm.getFields().add(newField);
+        destinationAnnotations.add(newWidget);
+        return true;
+    }
+
+    private static String generateUniqueFieldName(
+            String originalName, int pageIndex, Map<String, Integer> fieldNameCounters) {
+        String baseName = "page" + pageIndex + "_" + originalName;
+
+        Integer counter = fieldNameCounters.get(baseName);
+        if (counter == null) {
+            counter = 0;
+        } else {
+            counter++;
+        }
+        fieldNameCounters.put(baseName, counter);
+
+        return counter == 0 ? baseName : baseName + "_" + counter;
+    }
+
+    private static Map<PDAnnotationWidget, PDField> buildWidgetFieldMap(PDAcroForm acroForm) {
+        Map<PDAnnotationWidget, PDField> map = new HashMap<>();
+        if (acroForm == null) {
+            return map;
+        }
+        try {
+            for (PDField field : acroForm.getFieldTree()) {
+                List<PDAnnotationWidget> widgets = field.getWidgets();
+                if (widgets != null) {
+                    for (PDAnnotationWidget w : widgets) {
+                        if (w != null) {
+                            map.put(w, field);
+                        }
+                    }
+                }
+            }
+        } catch (Exception e) {
+            log.warn("Failed to build widget->field map: {}", e.getMessage(), e);
+        }
+        return map;
+    }
+}

app/common/src/main/java/stirling/software/common/util/GeneralUtils.java

@@ -9,13 +9,9 @@ import java.nio.charset.StandardCharsets;
 import java.nio.file.*;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.security.MessageDigest;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Enumeration;
-import java.util.List;
-import java.util.Locale;
-import java.util.Set;
-import java.util.UUID;
+import java.util.*;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
@@ -28,25 +24,37 @@ import com.fathzer.soft.javaluator.DoubleEvaluator;
 import io.github.pixee.security.HostValidator;
 import io.github.pixee.security.Urls;
 
+import lombok.experimental.UtilityClass;
 import lombok.extern.slf4j.Slf4j;
 
 import stirling.software.common.configuration.InstallationPathConfig;
 
 @Slf4j
+@UtilityClass
 public class GeneralUtils {
 
-    private static final Set<String> DEFAULT_VALID_SCRIPTS =
-            Set.of("png_to_webp.py", "split_photos.py");
-    private static final Set<String> DEFAULT_VALID_PIPELINE =
+    private final Set<String> DEFAULT_VALID_SCRIPTS = Set.of("png_to_webp.py", "split_photos.py");
+    private final Set<String> DEFAULT_VALID_PIPELINE =
             Set.of(
                     "OCR images.json",
                     "Prepare-pdfs-for-email.json",
                     "split-rotate-auto-rename.json");
 
-    private static final String DEFAULT_WEBUI_CONFIGS_DIR = "defaultWebUIConfigs";
-    private static final String PYTHON_SCRIPTS_DIR = "python";
+    private final String DEFAULT_WEBUI_CONFIGS_DIR = "defaultWebUIConfigs";
+    private final String PYTHON_SCRIPTS_DIR = "python";
+    private final RegexPatternUtils patternCache = RegexPatternUtils.getInstance();
+    // Valid size units used for convertSizeToBytes validation and parsing
+    private final Set<String> VALID_SIZE_UNITS = Set.of("B", "KB", "MB", "GB", "TB");
 
-    public static File convertMultipartFileToFile(MultipartFile multipartFile) throws IOException {
+    /*
+     * Converts a MultipartFile to a regular File with improved performance and security.
+     *
+     * @param multipartFile the multipart file to convert
+     * @return temporary File containing the multipart file data
+     * @throws IOException if I/O error occurs during conversion
+     * @throws IllegalArgumentException if file exceeds maximum allowed size
+     */
+    public File convertMultipartFileToFile(MultipartFile multipartFile) throws IOException {
         String customTempDir = System.getenv("STIRLING_TEMPFILES_DIRECTORY");
         if (customTempDir == null || customTempDir.isEmpty()) {
             customTempDir = System.getProperty("stirling.tempfiles.directory");
@@ -81,10 +89,137 @@ public class GeneralUtils {
         return tempFile;
     }
 
-    public static void deleteDirectory(Path path) throws IOException {
+    /*
+     * Gets the configured temporary directory, creating it if necessary.
+     *
+     * @return Path to the temporary directory
+     * @throws IOException if directory creation fails
+     */
+    private Path getTempDirectory() throws IOException {
+        String customTempDir = System.getenv("STIRLING_TEMPFILES_DIRECTORY");
+        if (customTempDir == null || customTempDir.isEmpty()) {
+            customTempDir = System.getProperty("stirling.tempfiles.directory");
+        }
+
+        Path tempDir;
+        if (customTempDir != null && !customTempDir.isEmpty()) {
+            tempDir = Path.of(customTempDir);
+        } else {
+            tempDir = Path.of(System.getProperty("java.io.tmpdir"), "stirling-pdf");
+        }
+
+        if (!Files.exists(tempDir)) {
+            Files.createDirectories(tempDir);
+        }
+
+        return tempDir;
+    }
+
+    /*
+     * Remove file extension
+     *
+     * <p>Uses fast string operations for common cases (valid extensions) and falls back to
+     * optimized regex for edge cases (no extension, hidden files, etc.).
+     *
+     * <ul>
+     *   <li>String operations avoid regex engine overhead for common cases
+     *   <li>Cached pattern compilation eliminates recompilation costs
+     *   <li>Fresh Matcher instances ensure thread safety
+     * </ul>
+     *
+     * @param filename the filename to process, may be null
+     * @return filename without extension, or "default" if input is null
+     */
+    public String removeExtension(String filename) {
+        if (filename == null) {
+            return "default";
+        }
+
+        if (filename.isEmpty()) {
+            return filename;
+        }
+
+        int dotIndex = filename.lastIndexOf('.');
+        if (dotIndex > 0 && dotIndex < filename.length() - 1) {
+            return filename.substring(0, dotIndex);
+        }
+
+        if (dotIndex == 0 || dotIndex == filename.length() - 1 || dotIndex == -1) {
+            return filename;
+        }
+
+        Pattern pattern = patternCache.getPattern(RegexPatternUtils.getExtensionRegex());
+        Matcher matcher = pattern.matcher(filename);
+        return matcher.find() ? matcher.replaceFirst("") : filename;
+    }
+
+    /*
+     * Append suffix to base name with null safety.
+     *
+     * @param baseName the base filename, null becomes "default"
+     * @param suffix the suffix to append, null becomes empty string
+     * @return concatenated string with null safety
+     */
+    public String appendSuffix(String baseName, String suffix) {
+        return (baseName == null ? "default" : baseName) + (suffix != null ? suffix : "");
+    }
+
+    /*
+     * Generate a PDF filename by removing extension from first file and adding suffix.
+     *
+     * <p>High-level utility method for common PDF naming scenarios. Handles null safety and uses
+     * extension removal.
+     *
+     * @param firstFilename the filename of the first file being, may be null
+     * @param suffix the suffix to append (e.g., "_merged.pdf")
+     * @return filename with suffix, or default name if input is null
+     */
+    public String generateFilename(String firstFilename, String suffix) {
+        String baseName = removeExtension(firstFilename);
+        return appendSuffix(baseName, suffix);
+    }
+
+    /*
+     * Process a list of filenames by removing extensions and adding suffix.
+     *
+     * <p>Efficiently processes multiple filenames using streaming operations and bulk operations
+     * where possible. Handles null safety for both input list and individual filenames.
+     *
+     * @param filenames the list of filenames to process, may be null
+     * @param suffix the suffix to append to each processed filename
+     * @param processor consumer to handle each processed filename, may be null
+     */
+    public void processFilenames(
+            List<String> filenames, String suffix, java.util.function.Consumer<String> processor) {
+        if (filenames == null || processor == null) {
+            return;
+        }
+
+        filenames.stream()
+                .map(filename -> appendSuffix(removeExtension(filename), suffix))
+                .forEach(processor);
+    }
+
+    /*
+     * Extract title from filename by removing extension, with fallback handling.
+     *
+     * <p>Returns "Untitled" for null or empty filenames, otherwise removes the extension using the
+     * optimized removeExtension method.
+     *
+     * @param filename the filename to extract title from, may be null
+     * @return the title without extension, or "Untitled" if input is null/empty
+     */
+    public String getTitleFromFilename(String filename) {
+        if (filename == null || filename.isEmpty()) {
+            return "Untitled";
+        }
+        return removeExtension(filename);
+    }
+
+    public void deleteDirectory(Path path) throws IOException {
         Files.walkFileTree(
                 path,
-                new SimpleFileVisitor<Path>() {
+                new SimpleFileVisitor<>() {
                     @Override
                     public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
                             throws IOException {
@@ -101,8 +236,18 @@ public class GeneralUtils {
                 });
     }
 
-    public static String convertToFileName(String name) {
-        String safeName = name.replaceAll("[^a-zA-Z0-9]", "_");
+    public String convertToFileName(String name) {
+        if (name == null) return "_";
+        StringBuilder safeNameBuilder = new StringBuilder(name.length());
+        for (int i = 0; i < name.length(); i++) {
+            char c = name.charAt(i);
+            if (Character.isLetterOrDigit(c)) {
+                safeNameBuilder.append(c);
+            } else {
+                safeNameBuilder.append('_');
+            }
+        }
+        String safeName = safeNameBuilder.toString();
         if (safeName.length() > 50) {
             safeName = safeName.substring(0, 50);
         }
@@ -110,19 +255,20 @@ public class GeneralUtils {
     }
 
     // Get resources from a location pattern
-    public static Resource[] getResourcesFromLocationPattern(
+    public Resource[] getResourcesFromLocationPattern(
             String locationPattern, ResourceLoader resourceLoader) throws Exception {
         // Normalize the path for file resources
-        if (locationPattern.startsWith("file:")) {
-            String rawPath = locationPattern.substring(5).replace("\\*", "").replace("/*", "");
+        String pattern = locationPattern;
+        if (pattern.startsWith("file:")) {
+            String rawPath = pattern.substring(5).replace("\\*", "").replace("/*", "");
             Path normalizePath = Paths.get(rawPath).normalize();
-            locationPattern = "file:" + normalizePath.toString().replace("\\", "/") + "/*";
+            pattern = "file:" + normalizePath.toString().replace("\\", "/") + "/*";
         }
         return ResourcePatternUtils.getResourcePatternResolver(resourceLoader)
-                .getResources(locationPattern);
+                .getResources(pattern);
     }
 
-    public static boolean isValidURL(String urlStr) {
+    public boolean isValidURL(String urlStr) {
         try {
             Urls.create(
                     urlStr, Urls.HTTP_PROTOCOLS, HostValidator.DENY_COMMON_INFRASTRUCTURE_TARGETS);
@@ -132,7 +278,25 @@ public class GeneralUtils {
         }
     }
 
-    public static boolean isURLReachable(String urlStr) {
+    /*
+     * Checks if a URL is reachable with proper timeout configuration and error handling.
+     *
+     * @param urlStr the URL string to check
+     * @return true if URL is reachable, false otherwise
+     */
+    public boolean isURLReachable(String urlStr) {
+        return isURLReachable(urlStr, 5000, 5000);
+    }
+
+    /*
+     * Checks if a URL is reachable with configurable timeouts.
+     *
+     * @param urlStr the URL string to check
+     * @param connectTimeout connection timeout in milliseconds
+     * @param readTimeout read timeout in milliseconds
+     * @return true if URL is reachable, false otherwise
+     */
+    public boolean isURLReachable(String urlStr, int connectTimeout, int readTimeout) {
         try {
             // Parse the URL
             URL url = URI.create(urlStr).toURL();
@@ -152,16 +316,19 @@ public class GeneralUtils {
             // Check if the URL is reachable
             HttpURLConnection connection = (HttpURLConnection) url.openConnection();
             connection.setRequestMethod("HEAD");
-            // connection.setConnectTimeout(5000); // Set connection timeout
-            // connection.setReadTimeout(5000);    // Set read timeout
+            connection.setConnectTimeout(connectTimeout);
+            connection.setReadTimeout(readTimeout);
+            connection.setInstanceFollowRedirects(false); // Security: prevent redirect loops
+
             int responseCode = connection.getResponseCode();
             return (200 <= responseCode && responseCode <= 399);
         } catch (Exception e) {
+            log.debug("URL {} is not reachable: {}", urlStr, e.getMessage());
             return false; // Return false in case of any exception
         }
     }
 
-    private static boolean isLocalAddress(String host) {
+    private boolean isLocalAddress(String host) {
         try {
             // Resolve DNS to IP address
             InetAddress address = InetAddress.getByName(host);
@@ -181,7 +348,14 @@ public class GeneralUtils {
         }
     }
 
-    public static File multipartToFile(MultipartFile multipart) throws IOException {
+    /*
+     * Improved multipart file conversion using the shared helper method.
+     *
+     * @param multipart the multipart file to convert
+     * @return temporary File containing the multipart file data
+     * @throws IOException if I/O error occurs during conversion
+     */
+    public File multipartToFile(MultipartFile multipart) throws IOException {
         Path tempFile = Files.createTempFile("overlay-", ".pdf");
         try (InputStream in = multipart.getInputStream();
                 FileOutputStream out = new FileOutputStream(tempFile.toFile())) {
@@ -194,54 +368,105 @@ public class GeneralUtils {
         return tempFile.toFile();
     }
 
-    public static Long convertSizeToBytes(String sizeStr) {
+    /*
+     * Supports TB/PB units and provides detailed error messages.
+     *
+     * @param sizeStr the size string to convert (e.g., "100MB", "1.5GB")
+     * @param defaultUnit the default unit to assume if none specified ("MB", "GB", etc.)
+     * @return size in bytes, or null if parsing fails
+     * @throws IllegalArgumentException if defaultUnit is invalid
+     */
+    public Long convertSizeToBytes(String sizeStr, String defaultUnit) {
         if (sizeStr == null) {
             return null;
         }
 
+        if (defaultUnit != null && !isValidSizeUnit(defaultUnit)) {
+            throw new IllegalArgumentException("Invalid default unit: " + defaultUnit);
+        }
+
         sizeStr = sizeStr.trim().toUpperCase();
         sizeStr = sizeStr.replace(",", ".").replace(" ", "");
+
         try {
-            if (sizeStr.endsWith("KB")) {
-                return (long)
-                        (Double.parseDouble(sizeStr.substring(0, sizeStr.length() - 2)) * 1024);
-            } else if (sizeStr.endsWith("MB")) {
+            if (sizeStr.endsWith("TB")) {
                 return (long)
                         (Double.parseDouble(sizeStr.substring(0, sizeStr.length() - 2))
-                                * 1024
-                                * 1024);
+                                * 1024L
+                                * 1024L
+                                * 1024L
+                                * 1024L);
             } else if (sizeStr.endsWith("GB")) {
                 return (long)
                         (Double.parseDouble(sizeStr.substring(0, sizeStr.length() - 2))
-                                * 1024
-                                * 1024
-                                * 1024);
-            } else if (sizeStr.endsWith("B")) {
+                                * 1024L
+                                * 1024L
+                                * 1024L);
+            } else if (sizeStr.endsWith("MB")) {
+                return (long)
+                        (Double.parseDouble(sizeStr.substring(0, sizeStr.length() - 2))
+                                * 1024L
+                                * 1024L);
+            } else if (sizeStr.endsWith("KB")) {
+                return (long)
+                        (Double.parseDouble(sizeStr.substring(0, sizeStr.length() - 2)) * 1024L);
+            } else if (!sizeStr.isEmpty() && sizeStr.charAt(sizeStr.length() - 1) == 'B') {
                 return Long.parseLong(sizeStr.substring(0, sizeStr.length() - 1));
             } else {
-                // Assume MB if no unit is specified
-                return (long) (Double.parseDouble(sizeStr) * 1024 * 1024);
+                // Use provided default unit or fall back to MB
+                String unit = defaultUnit != null ? defaultUnit.toUpperCase() : "MB";
+                double value = Double.parseDouble(sizeStr);
+                return switch (unit) {
+                    case "TB" -> (long) (value * 1024L * 1024L * 1024L * 1024L);
+                    case "GB" -> (long) (value * 1024L * 1024L * 1024L);
+                    case "MB" -> (long) (value * 1024L * 1024L);
+                    case "KB" -> (long) (value * 1024L);
+                    case "B" -> (long) value;
+                    default -> (long) (value * 1024L * 1024L); // Default to MB
+                };
             }
         } catch (NumberFormatException e) {
-            // The numeric part of the input string cannot be parsed, handle this case
+            log.warn("Failed to parse size string '{}': {}", sizeStr, e.getMessage());
+            return null;
         }
-
-        return null;
     }
 
-    public static String formatBytes(long bytes) {
+    /*
+     * Converts size string to bytes using MB as default unit.
+     *
+     * @param sizeStr the size string to convert
+     * @return size in bytes, or null if parsing fails
+     */
+    public Long convertSizeToBytes(String sizeStr) {
+        return convertSizeToBytes(sizeStr, "MB");
+    }
+
+    /* Validates if a string represents a valid size unit. */
+    private boolean isValidSizeUnit(String unit) {
+        // Use a precomputed Set for O(1) lookup, normalize using a locale-safe toUpperCase
+        return unit != null && VALID_SIZE_UNITS.contains(unit.toUpperCase(Locale.ROOT));
+    }
+
+    /* Enhanced byte formatting with TB/PB support and better precision. */
+    public String formatBytes(long bytes) {
+        if (bytes < 0) {
+            return "Invalid size";
+        }
+
         if (bytes < 1024) {
             return bytes + " B";
-        } else if (bytes < 1024 * 1024) {
+        } else if (bytes < 1024L * 1024L) {
             return String.format(Locale.US, "%.2f KB", bytes / 1024.0);
-        } else if (bytes < 1024 * 1024 * 1024) {
+        } else if (bytes < 1024L * 1024L * 1024L) {
             return String.format(Locale.US, "%.2f MB", bytes / (1024.0 * 1024.0));
-        } else {
+        } else if (bytes < 1024L * 1024L * 1024L * 1024L) {
             return String.format(Locale.US, "%.2f GB", bytes / (1024.0 * 1024.0 * 1024.0));
+        } else {
+            return String.format(Locale.US, "%.2f TB", bytes / (1024.0 * 1024.0 * 1024.0 * 1024.0));
         }
     }
 
-    public static List<Integer> parsePageList(String pages, int totalPages, boolean oneBased) {
+    public List<Integer> parsePageList(String pages, int totalPages, boolean oneBased) {
         if (pages == null) {
             return List.of(1); // Default to first page if input is null
         }
@@ -252,11 +477,11 @@ public class GeneralUtils {
         }
     }
 
-    public static List<Integer> parsePageList(String[] pages, int totalPages) {
+    public List<Integer> parsePageList(String[] pages, int totalPages) {
         return parsePageList(pages, totalPages, false);
     }
 
-    public static List<Integer> parsePageList(String[] pages, int totalPages, boolean oneBased) {
+    public List<Integer> parsePageList(String[] pages, int totalPages, boolean oneBased) {
         List<Integer> result = new ArrayList<>();
         int offset = oneBased ? 1 : 0;
         for (String page : pages) {
@@ -278,33 +503,72 @@ public class GeneralUtils {
         return result;
     }
 
-    public static List<Integer> evaluateNFunc(String expression, int maxValue) {
+    /*
+     * Enhanced mathematical expression evaluation with bounds checking and timeout protection.
+     *
+     * @param expression the mathematical expression containing 'n'
+     * @param maxValue the maximum value for 'n' and result bounds
+     * @return list of valid page numbers
+     * @throws IllegalArgumentException if expression is invalid or unsafe
+     */
+    public List<Integer> evaluateNFunc(String expression, int maxValue) {
+        if (expression == null || expression.trim().isEmpty()) {
+            throw new IllegalArgumentException("Expression cannot be null or empty");
+        }
+
+        if (maxValue <= 0 || maxValue > 10000) {
+            throw new IllegalArgumentException("maxValue must be between 1 and 10000 for safety");
+        }
+
         List<Integer> results = new ArrayList<>();
         DoubleEvaluator evaluator = new DoubleEvaluator();
 
-        // Validate the expression
-        if (!expression.matches("[0-9n+\\-*/() ]+")) {
-            throw new IllegalArgumentException("Invalid expression");
+        // Validate the expression format
+        if (!RegexPatternUtils.getInstance()
+                .getMathExpressionPattern()
+                .matcher(expression.trim())
+                .matches()) {
+            throw new IllegalArgumentException("Invalid expression format: " + expression);
         }
 
         for (int n = 1; n <= maxValue; n++) {
-            // Replace 'n' with the current value of n, correctly handling numbers before
-            // 'n'
-            String sanitizedExpression = sanitizeNFunction(expression, n);
-            Double result = evaluator.evaluate(sanitizedExpression);
+            try {
+                // Replace 'n' with the current value of n, correctly handling numbers before 'n'
+                String sanitizedExpression = sanitizeNFunction(expression.trim(), n);
+                Double result = evaluator.evaluate(sanitizedExpression);
 
-            // Check if the result is null or not within bounds
-            if (result == null) break;
+                // Check if the result is null or not within bounds
+                if (result == null || !Double.isFinite(result)) {
+                    continue;
+                }
 
-            if (result.intValue() > 0 && result.intValue() <= maxValue)
-                results.add(result.intValue());
+                int intResult = result.intValue();
+                if (intResult > 0 && intResult <= maxValue) {
+                    results.add(intResult);
+                }
+            } catch (Exception e) {
+                log.debug(
+                        "Failed to evaluate expression '{}' for n={}: {}",
+                        expression,
+                        n,
+                        e.getMessage());
+                // Continue with next value instead of breaking
+            }
         }
 
         return results;
     }
 
-    private static String sanitizeNFunction(String expression, int nValue) {
-        String sanitizedExpression = expression.replace(" ", "");
+    private String sanitizeNFunction(String expression, int nValue) {
+        // Remove all spaces using a specialized character removal
+        StringBuilder sb = new StringBuilder(expression.length());
+        for (int i = 0; i < expression.length(); i++) {
+            char c = expression.charAt(i);
+            if (c != ' ') {
+                sb.append(c);
+            }
+        }
+        String sanitizedExpression = sb.toString();
         String multiplyByOpeningRoundBracketPattern =
                 "([0-9n)])\\("; // example: n(n-1), 9(n-1), (n-1)(n-2)
         sanitizedExpression =
@@ -319,23 +583,45 @@ public class GeneralUtils {
         return sanitizedExpression;
     }
 
-    private static String insertMultiplicationBeforeN(String expression, int nValue) {
-        // Insert multiplication between a number and 'n' (e.g., "4n" becomes "4*n")
-        String withMultiplication = expression.replaceAll("(\\d)n", "$1*n");
+    private String insertMultiplicationBeforeN(String expression, int nValue) {
+        // Insert multiplication between a number and 'n' (e.g., "4n" becomes "4*n") using a loop
+        StringBuilder sb = new StringBuilder(expression.length() + 4); // +4 for possible extra '*'
+        for (int i = 0; i < expression.length(); i++) {
+            char c = expression.charAt(i);
+            sb.append(c);
+            if (Character.isDigit(c)
+                    && i + 1 < expression.length()
+                    && expression.charAt(i + 1) == 'n') {
+                sb.append('*');
+            }
+        }
+        String withMultiplication = sb.toString();
         withMultiplication = formatConsecutiveNsForNFunction(withMultiplication);
         // Now replace 'n' with its current value
         return withMultiplication.replace("n", String.valueOf(nValue));
     }
 
-    private static String formatConsecutiveNsForNFunction(String expression) {
+    private String formatConsecutiveNsForNFunction(String expression) {
         String text = expression;
-        while (text.matches(".*n{2,}.*")) {
-            text = text.replaceAll("(?<!n)n{2}", "n*n");
+        // Replace all consecutive 'nn' with 'n*n' until no more 'nn' is found
+        while (text.contains("nn")) {
+            StringBuilder sb = new StringBuilder(text.length() + 2); // +2 for possible extra '*'
+            int i = 0;
+            while (i < text.length()) {
+                if (i < text.length() - 1 && text.charAt(i) == 'n' && text.charAt(i + 1) == 'n') {
+                    sb.append("n*n");
+                    i += 2;
+                } else {
+                    sb.append(text.charAt(i));
+                    i++;
+                }
+            }
+            text = sb.toString();
         }
         return text;
     }
 
-    private static List<Integer> handlePart(String part, int totalPages, int offset) {
+    private List<Integer> handlePart(String part, int totalPages, int offset) {
         List<Integer> partResult = new ArrayList<>();
 
         // First check for n-syntax because it should not be processed as a range
@@ -361,7 +647,7 @@ public class GeneralUtils {
                     }
                 }
             } catch (NumberFormatException e) {
-                // Range is invalid, ignore this part
+                log.debug("Invalid range: {}", part);
             }
         } else {
             // This is a single page number
@@ -370,14 +656,14 @@ public class GeneralUtils {
                 if (pageNum >= 1 && pageNum <= totalPages) {
                     partResult.add(pageNum - 1 + offset);
                 }
-            } catch (NumberFormatException ignored) {
-                // Ignore invalid numbers
+            } catch (NumberFormatException e) {
+                log.debug("Invalid page number: {}", part);
             }
         }
         return partResult;
     }
 
-    public static boolean createDir(String path) {
+    public boolean createDir(String path) {
         Path folder = Paths.get(path);
         if (!Files.exists(folder)) {
             try {
@@ -390,7 +676,7 @@ public class GeneralUtils {
         return true;
     }
 
-    public static boolean isValidUUID(String uuid) {
+    public boolean isValidUUID(String uuid) {
         if (uuid == null) {
             return false;
         }
@@ -406,7 +692,7 @@ public class GeneralUtils {
      *                  Internal Implementation Details                       *
      *------------------------------------------------------------------------*/
 
-    public static void saveKeyToSettings(String key, Object newValue) throws IOException {
+    public void saveKeyToSettings(String key, Object newValue) throws IOException {
         String[] keyArray = key.split("\\.");
         Path settingsPath = Paths.get(InstallationPathConfig.getSettingsPath());
         YamlHelper settingsYaml = new YamlHelper(settingsPath);
@@ -414,48 +700,67 @@ public class GeneralUtils {
         settingsYaml.saveOverride(settingsPath);
     }
 
-    public static String generateMachineFingerprint() {
+    /*
+     * Machine fingerprint generation with better error logging and fallbacks.
+     *
+     * @return unique machine fingerprint or "GenericID" if generation fails
+     */
+    public String generateMachineFingerprint() {
         try {
-            // Get the MAC address
             StringBuilder sb = new StringBuilder();
+
+            // Try to get MAC address from primary network interface
             InetAddress ip = InetAddress.getLocalHost();
             NetworkInterface network = NetworkInterface.getByInetAddress(ip);
 
-            if (network == null) {
+            if (network == null || network.getHardwareAddress() == null) {
+                // Fallback: iterate through all network interfaces
                 Enumeration<NetworkInterface> networks = NetworkInterface.getNetworkInterfaces();
                 while (networks.hasMoreElements()) {
                     NetworkInterface net = networks.nextElement();
-                    byte[] mac = net.getHardwareAddress();
-                    if (mac != null) {
-                        for (int i = 0; i < mac.length; i++) {
-                            sb.append(String.format("%02X", mac[i]));
+                    if (net.isUp() && !net.isLoopback() && !net.isVirtual()) {
+                        byte[] mac = net.getHardwareAddress();
+                        if (mac != null && mac.length > 0) {
+                            for (byte b : mac) {
+                                sb.append(String.format("%02X", b));
+                            }
+                            break; // Use the first valid network interface
                         }
-                        break; // Use the first network interface with a MAC address
                     }
                 }
             } else {
                 byte[] mac = network.getHardwareAddress();
                 if (mac != null) {
-                    for (int i = 0; i < mac.length; i++) {
-                        sb.append(String.format("%02X", mac[i]));
+                    for (byte b : mac) {
+                        sb.append(String.format("%02X", b));
                     }
                 }
             }
 
-            // Hash the MAC address for privacy and consistency
+            // If no MAC address found, use hostname as fallback
+            if (sb.length() == 0) {
+                String hostname = InetAddress.getLocalHost().getHostName();
+                sb.append(hostname != null ? hostname : "unknown-host");
+                log.warn("No MAC address found, using hostname for fingerprint generation");
+            }
+
+            // Hash the collected data for privacy and consistency
             MessageDigest md = MessageDigest.getInstance("SHA-256");
             byte[] hash = md.digest(sb.toString().getBytes(StandardCharsets.UTF_8));
             StringBuilder fingerprint = new StringBuilder();
             for (byte b : hash) {
                 fingerprint.append(String.format("%02x", b));
             }
+
+            log.debug("Successfully generated machine fingerprint");
             return fingerprint.toString();
         } catch (Exception e) {
+            log.warn("Failed to generate machine fingerprint: {}", e.getMessage());
             return "GenericID";
         }
     }
 
-    /**
+    /*
      * Extracts the default pipeline configurations from the classpath to the installation path.
      * Creates directories if needed and copies default JSON files.
      *
@@ -464,7 +769,7 @@ public class GeneralUtils {
      *
      * @throws IOException if an I/O error occurs during file operations
      */
-    public static void extractPipeline() throws IOException {
+    public void extractPipeline() throws IOException {
         Path pipelineDir =
                 Paths.get(InstallationPathConfig.getPipelinePath(), DEFAULT_WEBUI_CONFIGS_DIR);
         Files.createDirectories(pipelineDir);
@@ -486,7 +791,7 @@ public class GeneralUtils {
         }
     }
 
-    /**
+    /*
      * Extracts the specified Python script from the classpath to the installation path. Validates
      * name and copies file atomically when possible, overwriting existing.
      *
@@ -497,7 +802,7 @@ public class GeneralUtils {
      * @throws IllegalArgumentException if the script name is invalid or not allowed
      * @throws IOException if an I/O error occurs
      */
-    public static Path extractScript(String scriptName) throws IOException {
+    public Path extractScript(String scriptName) throws IOException {
         // Validate input
         if (scriptName == null || scriptName.trim().isEmpty()) {
             throw new IllegalArgumentException("scriptName must not be null or empty");
@@ -530,15 +835,14 @@ public class GeneralUtils {
         return target;
     }
 
-    /**
+    /*
      * Copies a resource from the classpath to a specified target file.
      *
      * @param resource the ClassPathResource to copy
      * @param target the target Path where the resource will be copied
      * @throws IOException if an I/O error occurs during the copy operation
      */
-    private static void copyResourceToFile(ClassPathResource resource, Path target)
-            throws IOException {
+    private void copyResourceToFile(ClassPathResource resource, Path target) throws IOException {
         Path dir = target.getParent();
         Path tmp = Files.createTempFile(dir, target.getFileName().toString(), ".tmp");
         try (InputStream in = resource.getInputStream()) {
@@ -573,7 +877,7 @@ public class GeneralUtils {
         }
     }
 
-    public static boolean isVersionHigher(String currentVersion, String compareVersion) {
+    public boolean isVersionHigher(String currentVersion, String compareVersion) {
         if (currentVersion == null || compareVersion == null) {
             return false;
         }
@@ -601,4 +905,67 @@ public class GeneralUtils {
         // If all components so far are equal, the longer version is considered higher
         return current.length > compare.length;
     }
+
+    /**
+     * Optimizes a PDF using Ghostscript with ebook settings for better e-reader compatibility. Uses
+     * -dPDFSETTINGS=/ebook -dFastWebView=true settings to create an optimized PDF.
+     *
+     * @param inputPdfBytes Original PDF as byte array
+     * @return Optimized PDF as byte array
+     * @throws IOException if Ghostscript optimization fails
+     */
+    public byte[] optimizePdfWithGhostscript(byte[] inputPdfBytes) throws IOException {
+        Path tempInput = null;
+        Path tempOutput = null;
+
+        try {
+            tempInput = Files.createTempFile("gs_input_", ".pdf");
+            tempOutput = Files.createTempFile("gs_output_", ".pdf");
+
+            Files.write(tempInput, inputPdfBytes);
+
+            List<String> command = new ArrayList<>();
+            command.add("gs");
+            command.add("-sDEVICE=pdfwrite");
+            command.add("-dPDFSETTINGS=/ebook");
+            command.add("-dFastWebView=true");
+            command.add("-dNOPAUSE");
+            command.add("-dQUIET");
+            command.add("-dBATCH");
+            command.add("-sOutputFile=" + tempOutput.toString());
+            command.add(tempInput.toString());
+
+            ProcessExecutor.ProcessExecutorResult result =
+                    ProcessExecutor.getInstance(ProcessExecutor.Processes.GHOSTSCRIPT)
+                            .runCommandWithOutputHandling(command);
+
+            if (result.getRc() != 0) {
+                log.warn(
+                        "Ghostscript ebook optimization failed with return code: {}",
+                        result.getRc());
+                throw ExceptionUtils.createGhostscriptCompressionException();
+            }
+
+            return Files.readAllBytes(tempOutput);
+
+        } catch (Exception e) {
+            log.warn("Ghostscript ebook optimization failed", e);
+            throw ExceptionUtils.createGhostscriptCompressionException(e);
+        } finally {
+            if (tempInput != null) {
+                try {
+                    Files.deleteIfExists(tempInput);
+                } catch (IOException e) {
+                    log.warn("Failed to delete temp input file: {}", tempInput, e);
+                }
+            }
+            if (tempOutput != null) {
+                try {
+                    Files.deleteIfExists(tempOutput);
+                } catch (IOException e) {
+                    log.warn("Failed to delete temp output file: {}", tempOutput, e);
+                }
+            }
+        }
+    }
 }

app/common/src/main/java/stirling/software/common/util/ImageProcessingUtils.java

@@ -85,19 +85,16 @@ public class ImageProcessingUtils {
                 return 0;
             }
             int orientationTag = directory.getInt(ExifSubIFDDirectory.TAG_ORIENTATION);
-            switch (orientationTag) {
-                case 1:
-                    return 0;
-                case 6:
-                    return 90;
-                case 3:
-                    return 180;
-                case 8:
-                    return 270;
-                default:
+            return switch (orientationTag) {
+                case 1 -> 0;
+                case 6 -> 90;
+                case 3 -> 180;
+                case 8 -> 270;
+                default -> {
                     log.warn("Unknown orientation tag: {}", orientationTag);
-                    return 0;
-            }
+                    yield 0;
+                }
+            };
         } catch (ImageProcessingException | MetadataException e) {
             return 0;
         }

app/common/src/main/java/stirling/software/common/util/JarPathUtil.java

@@ -43,26 +43,45 @@ public class JarPathUtil {
     }
 
     /**
-     * Gets the path to the restart-helper.jar file Expected to be in the same directory as the main
-     * JAR
+     * Gets the path to the restart-helper.jar file. Checks multiple possible locations: 1. Same
+     * directory as the main JAR (production deployment) 2. ./build/libs/restart-helper.jar
+     * (development build) 3. app/common/build/libs/restart-helper.jar (multi-module build)
      *
      * @return Path to restart-helper.jar, or null if not found
      */
     public static Path restartHelperJar() {
         Path appJar = currentJar();
-        if (appJar == null) {
-            return null;
+
+        // Define possible locations to check (in order of preference)
+        Path[] possibleLocations = new Path[4];
+
+        // Location 1: Same directory as main JAR (production)
+        if (appJar != null) {
+            possibleLocations[0] = appJar.getParent().resolve("restart-helper.jar");
         }
 
-        Path helperJar = appJar.getParent().resolve("restart-helper.jar");
+        // Location 2: ./build/libs/ (development build)
+        possibleLocations[1] = Paths.get("build", "libs", "restart-helper.jar").toAbsolutePath();
 
-        if (Files.isRegularFile(helperJar)) {
-            log.debug("Restart helper JAR located at: {}", helperJar);
-            return helperJar;
-        } else {
-            log.warn("Restart helper JAR not found at: {}", helperJar);
-            return null;
+        // Location 3: app/common/build/libs/ (multi-module build)
+        possibleLocations[2] =
+                Paths.get("app", "common", "build", "libs", "restart-helper.jar").toAbsolutePath();
+
+        // Location 4: Current working directory
+        possibleLocations[3] = Paths.get("restart-helper.jar").toAbsolutePath();
+
+        // Check each location
+        for (Path location : possibleLocations) {
+            if (location != null && Files.isRegularFile(location)) {
+                log.info("Restart helper JAR found at: {}", location);
+                return location;
+            } else if (location != null) {
+                log.debug("Restart helper JAR not found at: {}", location);
+            }
         }
+
+        log.warn("Restart helper JAR not found in any expected location");
+        return null;
     }
 
     /**

app/common/src/main/java/stirling/software/common/util/PDFService.java

@@ -0,0 +1,35 @@
+package stirling.software.common.util;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.pdfbox.multipdf.PDFMergerUtility;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.springframework.stereotype.Service;
+
+import lombok.RequiredArgsConstructor;
+
+import stirling.software.common.service.CustomPDFDocumentFactory;
+
+@Service
+@RequiredArgsConstructor
+public class PDFService {
+
+    private final CustomPDFDocumentFactory pdfDocumentFactory;
+
+    /*
+     * Merge multiple PDF documents into a single PDF document
+     *
+     * @param documents List of PDDocument to be merged
+     * @return Merged PDDocument
+     * @throws IOException If an error occurs during merging
+     */
+    public PDDocument mergeDocuments(List<PDDocument> documents) throws IOException {
+        PDDocument merged = pdfDocumentFactory.createNewDocument();
+        PDFMergerUtility merger = new PDFMergerUtility();
+        for (PDDocument doc : documents) {
+            merger.appendDocument(merged, doc);
+        }
+        return merged;
+    }
+}

app/common/src/main/java/stirling/software/common/util/PDFToFile.java

@@ -25,18 +25,22 @@ import com.vladsch.flexmark.util.data.MutableDataSet;
 
 import io.github.pixee.security.Filenames;
 
-import lombok.NoArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
 import stirling.software.common.util.ProcessExecutor.ProcessExecutorResult;
 
 @Slf4j
-@NoArgsConstructor
 public class PDFToFile {
 
+    private final TempFileManager tempFileManager;
+
+    public PDFToFile(TempFileManager tempFileManager) {
+        this.tempFileManager = tempFileManager;
+    }
+
     public ResponseEntity<byte[]> processPdfToMarkdown(MultipartFile inputFile)
             throws IOException, InterruptedException {
-        if (!"application/pdf".equals(inputFile.getContentType())) {
+        if (!MediaType.APPLICATION_PDF_VALUE.equals(inputFile.getContentType())) {
             return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
         }
 
@@ -71,15 +75,12 @@ public class PDFToFile {
             pdfBaseName = originalPdfFileName.substring(0, originalPdfFileName.lastIndexOf('.'));
         }
 
-        Path tempInputFile = null;
-        Path tempOutputDir = null;
         byte[] fileBytes;
-        String fileName = "temp.file";
+        String fileName;
 
-        try {
-            tempInputFile = Files.createTempFile("input_", ".pdf");
-            inputFile.transferTo(tempInputFile);
-            tempOutputDir = Files.createTempDirectory("output_");
+        try (TempFile tempInputFile = new TempFile(tempFileManager, ".pdf");
+                TempDirectory tempOutputDir = new TempDirectory(tempFileManager)) {
+            inputFile.transferTo(tempInputFile.getFile());
 
             List<String> command =
                     new ArrayList<>(
@@ -88,14 +89,16 @@ public class PDFToFile {
                                     "-s",
                                     "-noframes",
                                     "-c",
-                                    tempInputFile.toString(),
+                                    tempInputFile.getAbsolutePath(),
                                     pdfBaseName));
 
             ProcessExecutorResult returnCode =
                     ProcessExecutor.getInstance(ProcessExecutor.Processes.PDFTOHTML)
-                            .runCommandWithOutputHandling(command, tempOutputDir.toFile());
+                            .runCommandWithOutputHandling(
+                                    command, tempOutputDir.getPath().toFile());
             // Process HTML files to Markdown
-            File[] outputFiles = Objects.requireNonNull(tempOutputDir.toFile().listFiles());
+            File[] outputFiles =
+                    Objects.requireNonNull(tempOutputDir.getPath().toFile().listFiles());
             List<File> markdownFiles = new ArrayList<>();
 
             // Convert HTML files to Markdown
@@ -105,7 +108,7 @@ public class PDFToFile {
                     String markdown = htmlToMarkdownConverter.convert(html);
 
                     String mdFileName = outputFile.getName().replace(".html", ".md");
-                    File mdFile = new File(tempOutputDir.toFile(), mdFileName);
+                    File mdFile = new File(tempOutputDir.getPath().toFile(), mdFileName);
                     Files.writeString(mdFile.toPath(), markdown);
                     markdownFiles.add(mdFile);
                 }
@@ -142,10 +145,6 @@ public class PDFToFile {
 
                 fileBytes = byteArrayOutputStream.toByteArray();
             }
-
-        } finally {
-            if (tempInputFile != null) Files.deleteIfExists(tempInputFile);
-            if (tempOutputDir != null) FileUtils.deleteDirectory(tempOutputDir.toFile());
         }
         return WebResponseUtils.bytesToWebResponse(
                 fileBytes, fileName, MediaType.APPLICATION_OCTET_STREAM);
@@ -153,7 +152,7 @@ public class PDFToFile {
 
     public ResponseEntity<byte[]> processPdfToHtml(MultipartFile inputFile)
             throws IOException, InterruptedException {
-        if (!"application/pdf".equals(inputFile.getContentType())) {
+        if (!MediaType.APPLICATION_PDF_VALUE.equals(inputFile.getContentType())) {
             return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
         }
 
@@ -164,19 +163,18 @@ public class PDFToFile {
             pdfBaseName = originalPdfFileName.substring(0, originalPdfFileName.lastIndexOf('.'));
         }
 
-        Path tempInputFile = null;
-        Path tempOutputDir = null;
         byte[] fileBytes;
-        String fileName = "temp.file";
+        String fileName;
+
+        try (TempFile inputFileTemp = new TempFile(tempFileManager, ".pdf");
+                TempDirectory outputDirTemp = new TempDirectory(tempFileManager)) {
+
+            Path tempInputFile = inputFileTemp.getPath();
+            Path tempOutputDir = outputDirTemp.getPath();
 
-        try {
             // Save the uploaded file to a temporary location
-            tempInputFile = Files.createTempFile("input_", ".pdf");
             inputFile.transferTo(tempInputFile);
 
-            // Prepare the output directory
-            tempOutputDir = Files.createTempDirectory("output_");
-
             // Run the pdftohtml command with complex output
             List<String> command =
                     new ArrayList<>(
@@ -208,11 +206,6 @@ public class PDFToFile {
                 log.error("Exception writing zip", e);
             }
             fileBytes = byteArrayOutputStream.toByteArray();
-
-        } finally {
-            // Clean up the temporary files
-            if (tempInputFile != null) Files.deleteIfExists(tempInputFile);
-            if (tempOutputDir != null) FileUtils.deleteDirectory(tempOutputDir.toFile());
         }
 
         return WebResponseUtils.bytesToWebResponse(
@@ -223,14 +216,14 @@ public class PDFToFile {
             MultipartFile inputFile, String outputFormat, String libreOfficeFilter)
             throws IOException, InterruptedException {
 
-        if (!"application/pdf".equals(inputFile.getContentType())) {
+        if (!MediaType.APPLICATION_PDF_VALUE.equals(inputFile.getContentType())) {
             return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
         }
 
         // Get the original PDF file name without the extension
         String originalPdfFileName = Filenames.toSimpleFileName(inputFile.getOriginalFilename());
 
-        if (originalPdfFileName == null || "".equals(originalPdfFileName.trim())) {
+        if (originalPdfFileName == null || originalPdfFileName.trim().isEmpty()) {
             originalPdfFileName = "output.pdf";
         }
         // Assume file is pdf if no extension
@@ -245,19 +238,18 @@ public class PDFToFile {
             return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
         }
 
-        Path tempInputFile = null;
-        Path tempOutputDir = null;
         byte[] fileBytes;
-        String fileName = "temp.file";
+        String fileName;
+
+        try (TempFile inputFileTemp = new TempFile(tempFileManager, ".pdf");
+                TempDirectory outputDirTemp = new TempDirectory(tempFileManager)) {
+
+            Path tempInputFile = inputFileTemp.getPath();
+            Path tempOutputDir = outputDirTemp.getPath();
 
-        try {
             // Save the uploaded file to a temporary location
-            tempInputFile = Files.createTempFile("input_", ".pdf");
             inputFile.transferTo(tempInputFile);
 
-            // Prepare the output directory
-            tempOutputDir = Files.createTempDirectory("output_");
-
             // Run the LibreOffice command
             List<String> command =
                     new ArrayList<>(
@@ -308,11 +300,6 @@ public class PDFToFile {
 
                 fileBytes = byteArrayOutputStream.toByteArray();
             }
-
-        } finally {
-            // Clean up the temporary files
-            Files.deleteIfExists(tempInputFile);
-            if (tempOutputDir != null) FileUtils.deleteDirectory(tempOutputDir.toFile());
         }
         return WebResponseUtils.bytesToWebResponse(
                 fileBytes, fileName, MediaType.APPLICATION_OCTET_STREAM);

app/common/src/main/java/stirling/software/common/util/PdfAttachmentHandler.java

@@ -8,7 +8,9 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.text.SimpleDateFormat;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
 import java.util.ArrayList;
 import java.util.Base64;
 import java.util.Date;
@@ -18,7 +20,6 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
-import java.util.TimeZone;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -37,6 +38,7 @@ import org.apache.pdfbox.pdmodel.interactive.annotation.PDAppearanceStream;
 import org.apache.pdfbox.text.PDFTextStripper;
 import org.apache.pdfbox.text.TextPosition;
 import org.jetbrains.annotations.NotNull;
+import org.springframework.http.MediaType;
 import org.springframework.web.multipart.MultipartFile;
 
 import lombok.Data;
@@ -118,7 +120,7 @@ public class PdfAttachmentHandler {
             public String getContentType() {
                 return attachment.getContentType() != null
                         ? attachment.getContentType()
-                        : "application/octet-stream";
+                        : MediaType.APPLICATION_OCTET_STREAM_VALUE;
             }
 
             @Override
@@ -256,10 +258,7 @@ public class PdfAttachmentHandler {
 
         if (contentIdMap.isEmpty()) return htmlContent;
 
-        Pattern cidPattern =
-                Pattern.compile(
-                        "(?i)<img[^>]*\\ssrc\\s*=\\s*['\"]cid:([^'\"]+)['\"][^>]*>",
-                        Pattern.CASE_INSENSITIVE);
+        Pattern cidPattern = RegexPatternUtils.getInstance().getInlineCidImagePattern();
         Matcher matcher = cidPattern.matcher(htmlContent);
 
         StringBuilder result = new StringBuilder();
@@ -289,11 +288,15 @@ public class PdfAttachmentHandler {
 
     public static String formatEmailDate(Date date) {
         if (date == null) return "";
+        return formatEmailDate(ZonedDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault()));
+    }
 
-        SimpleDateFormat formatter =
-                new SimpleDateFormat("EEE, MMM d, yyyy 'at' h:mm a z", Locale.ENGLISH);
-        formatter.setTimeZone(TimeZone.getTimeZone("UTC"));
-        return formatter.format(date);
+    public static String formatEmailDate(ZonedDateTime dateTime) {
+        if (dateTime == null) return "";
+
+        DateTimeFormatter formatter =
+                DateTimeFormatter.ofPattern("EEE, MMM d, yyyy 'at' h:mm a z", Locale.ENGLISH);
+        return dateTime.withZoneSameInstant(ZoneId.of("UTC")).format(formatter);
     }
 
     @Data
@@ -313,121 +316,20 @@ public class PdfAttachmentHandler {
         }
     }
 
-    public static class AttachmentMarkerPositionFinder extends PDFTextStripper {
-        @Getter private final List<MarkerPosition> positions = new ArrayList<>();
-        private int currentPageIndex;
-        protected boolean sortByPosition;
-        private boolean isInAttachmentSection;
-        private boolean attachmentSectionFound;
-        private final StringBuilder currentText = new StringBuilder();
-
-        private static final Pattern ATTACHMENT_SECTION_PATTERN =
-                Pattern.compile("attachments\\s*\\(\\d+\\)", Pattern.CASE_INSENSITIVE);
-
-        private static final Pattern FILENAME_PATTERN =
-                Pattern.compile("@\\s*([^\\s\\(]+(?:\\.[a-zA-Z0-9]+)?)");
-
-        public AttachmentMarkerPositionFinder() {
-            super();
-            this.currentPageIndex = 0;
-            this.sortByPosition = false; // Disable sorting to preserve document order
-            this.isInAttachmentSection = false;
-            this.attachmentSectionFound = false;
-        }
-
-        @Override
-        public String getText(PDDocument document) throws IOException {
-            super.getText(document);
-
-            if (sortByPosition) {
-                positions.sort(
-                        (a, b) -> {
-                            int pageCompare = Integer.compare(a.getPageIndex(), b.getPageIndex());
-                            if (pageCompare != 0) return pageCompare;
-                            return Float.compare(
-                                    b.getY(), a.getY()); // Descending Y per PDF coordinate system
-                        });
-            }
-
-            return ""; // Return empty string as we only need positions
-        }
-
-        @Override
-        protected void startPage(PDPage page) throws IOException {
-            super.startPage(page);
-        }
-
-        @Override
-        protected void endPage(PDPage page) throws IOException {
-            currentPageIndex++;
-            super.endPage(page);
-        }
-
-        @Override
-        protected void writeString(String string, List<TextPosition> textPositions)
-                throws IOException {
-            String lowerString = string.toLowerCase();
-
-            if (ATTACHMENT_SECTION_PATTERN.matcher(lowerString).find()) {
-                isInAttachmentSection = true;
-                attachmentSectionFound = true;
-            }
-
-            if (isInAttachmentSection
-                    && (lowerString.contains("</body>")
-                            || lowerString.contains("</html>")
-                            || (attachmentSectionFound
-                                    && lowerString.trim().isEmpty()
-                                    && string.length() > 50))) {
-                isInAttachmentSection = false;
-            }
-
-            if (isInAttachmentSection) {
-                currentText.append(string);
-
-                for (int i = 0; (i = string.indexOf(ATTACHMENT_MARKER, i)) != -1; i++) {
-                    if (i < textPositions.size()) {
-                        TextPosition textPosition = textPositions.get(i);
-
-                        String filename = extractFilenameAfterMarker(string, i);
-
-                        MarkerPosition position =
-                                new MarkerPosition(
-                                        currentPageIndex,
-                                        textPosition.getXDirAdj(),
-                                        textPosition.getYDirAdj(),
-                                        ATTACHMENT_MARKER,
-                                        filename);
-                        positions.add(position);
-                    }
-                }
-            }
-            super.writeString(string, textPositions);
-        }
-
-        @Override
-        public void setSortByPosition(boolean sortByPosition) {
-            this.sortByPosition = sortByPosition;
-        }
-
-        private String extractFilenameAfterMarker(String text, int markerIndex) {
-            String afterMarker = text.substring(markerIndex + 1);
-
-            Matcher matcher = FILENAME_PATTERN.matcher("@" + afterMarker);
-            if (matcher.find()) {
-                return matcher.group(1);
-            }
-
-            String[] parts = afterMarker.split("[\\s\\(\\)]+");
-            for (String part : parts) {
-                part = part.trim();
-                if (part.length() > 3 && part.contains(".")) {
-                    return part;
-                }
-            }
-
-            return null;
-        }
+    private static String normalizeFilename(String filename) {
+        if (filename == null) return "";
+        String normalized = filename.toLowerCase().trim();
+        normalized =
+                RegexPatternUtils.getInstance()
+                        .getWhitespacePattern()
+                        .matcher(normalized)
+                        .replaceAll(" ");
+        normalized =
+                RegexPatternUtils.getInstance()
+                        .getPattern("[^a-zA-Z0-9._-]")
+                        .matcher(normalized)
+                        .replaceAll("");
+        return normalized;
     }
 
     private static Map<Integer, String> addAttachmentsToDocumentWithMapping(
@@ -607,12 +509,122 @@ public class PdfAttachmentHandler {
         return null;
     }
 
-    private static String normalizeFilename(String filename) {
-        if (filename == null) return "";
-        return filename.toLowerCase()
-                .trim()
-                .replaceAll("\\s+", " ")
-                .replaceAll("[^a-zA-Z0-9._-]", "");
+    public static class AttachmentMarkerPositionFinder extends PDFTextStripper {
+        private static final Pattern ATTACHMENT_SECTION_PATTERN =
+                RegexPatternUtils.getInstance().getAttachmentSectionPattern();
+        private static final Pattern FILENAME_PATTERN =
+                RegexPatternUtils.getInstance().getAttachmentFilenamePattern();
+        @Getter private final List<MarkerPosition> positions = new ArrayList<>();
+        private final StringBuilder currentText = new StringBuilder();
+        protected boolean sortByPosition;
+        private int currentPageIndex;
+        private boolean isInAttachmentSection;
+        private boolean attachmentSectionFound;
+
+        public AttachmentMarkerPositionFinder() {
+            super();
+            this.currentPageIndex = 0;
+            this.sortByPosition = false; // Disable sorting to preserve document order
+            this.isInAttachmentSection = false;
+            this.attachmentSectionFound = false;
+        }
+
+        @Override
+        public String getText(PDDocument document) throws IOException {
+            super.getText(document);
+
+            if (sortByPosition) {
+                positions.sort(
+                        (a, b) -> {
+                            int pageCompare = Integer.compare(a.getPageIndex(), b.getPageIndex());
+                            if (pageCompare != 0) return pageCompare;
+                            return Float.compare(
+                                    b.getY(), a.getY()); // Descending Y per PDF coordinate system
+                        });
+            }
+
+            return ""; // Return empty string as we only need positions
+        }
+
+        @Override
+        protected void startPage(PDPage page) throws IOException {
+            super.startPage(page);
+        }
+
+        @Override
+        protected void endPage(PDPage page) throws IOException {
+            currentPageIndex++;
+            super.endPage(page);
+        }
+
+        @Override
+        protected void writeString(String string, List<TextPosition> textPositions)
+                throws IOException {
+            String lowerString = string.toLowerCase();
+
+            if (ATTACHMENT_SECTION_PATTERN.matcher(lowerString).find()) {
+                isInAttachmentSection = true;
+                attachmentSectionFound = true;
+            }
+
+            if (isInAttachmentSection
+                    && (lowerString.contains("</body>")
+                            || lowerString.contains("</html>")
+                            || (attachmentSectionFound
+                                    && lowerString.trim().isEmpty()
+                                    && string.length() > 50))) {
+                isInAttachmentSection = false;
+            }
+
+            if (isInAttachmentSection) {
+                currentText.append(string);
+
+                for (int i = 0; (i = string.indexOf(ATTACHMENT_MARKER, i)) != -1; i++) {
+                    if (i < textPositions.size()) {
+                        TextPosition textPosition = textPositions.get(i);
+
+                        String filename = extractFilenameAfterMarker(string, i);
+
+                        MarkerPosition position =
+                                new MarkerPosition(
+                                        currentPageIndex,
+                                        textPosition.getXDirAdj(),
+                                        textPosition.getYDirAdj(),
+                                        ATTACHMENT_MARKER,
+                                        filename);
+                        positions.add(position);
+                    }
+                }
+            }
+            super.writeString(string, textPositions);
+        }
+
+        @Override
+        public void setSortByPosition(boolean sortByPosition) {
+            this.sortByPosition = sortByPosition;
+        }
+
+        private String extractFilenameAfterMarker(String text, int markerIndex) {
+            String afterMarker = text.substring(markerIndex + 1);
+
+            Matcher matcher = FILENAME_PATTERN.matcher("@" + afterMarker);
+            if (matcher.find()) {
+                return matcher.group(1);
+            }
+
+            String[] parts =
+                    RegexPatternUtils.getInstance()
+                            .getWhitespaceParenthesesSplitPattern()
+                            .split(afterMarker);
+            for (String part : parts) {
+                part = part.trim();
+                if (part.length() > 3 && part.contains(".")) {
+                    return part;
+                }
+            }
+
+            return null;
+        }
     }
 
     private static void addAttachmentAnnotationToPageWithMapping(

app/common/src/main/java/stirling/software/common/util/PdfToCbrUtils.java

@@ -0,0 +1,173 @@
+package stirling.software.common.util;
+
+import java.awt.image.BufferedImage;
+import java.io.ByteArrayOutputStream;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.List;
+
+import javax.imageio.ImageIO;
+
+import org.apache.commons.io.FilenameUtils;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.rendering.ImageType;
+import org.apache.pdfbox.rendering.PDFRenderer;
+import org.springframework.web.multipart.MultipartFile;
+
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.common.service.CustomPDFDocumentFactory;
+import stirling.software.common.util.ProcessExecutor.ProcessExecutorResult;
+
+@Slf4j
+public class PdfToCbrUtils {
+
+    public static byte[] convertPdfToCbr(
+            MultipartFile pdfFile, int dpi, CustomPDFDocumentFactory pdfDocumentFactory)
+            throws IOException {
+
+        validatePdfFile(pdfFile);
+
+        try (PDDocument document = pdfDocumentFactory.load(pdfFile)) {
+            if (document.getNumberOfPages() == 0) {
+                throw new IllegalArgumentException("PDF file contains no pages");
+            }
+
+            return createCbrFromPdf(document, dpi);
+        }
+    }
+
+    private static void validatePdfFile(MultipartFile file) {
+        if (file == null || file.isEmpty()) {
+            throw new IllegalArgumentException("File cannot be null or empty");
+        }
+
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            throw new IllegalArgumentException("File must have a name");
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        if (!"pdf".equals(extension)) {
+            throw new IllegalArgumentException("File must be a PDF");
+        }
+    }
+
+    private static byte[] createCbrFromPdf(PDDocument document, int dpi) throws IOException {
+        PDFRenderer pdfRenderer = new PDFRenderer(document);
+
+        Path tempDir = Files.createTempDirectory("stirling-pdf-cbr-");
+        List<Path> generatedImages = new ArrayList<>();
+        try {
+            int totalPages = document.getNumberOfPages();
+
+            for (int pageIndex = 0; pageIndex < totalPages; pageIndex++) {
+                try {
+                    BufferedImage image =
+                            pdfRenderer.renderImageWithDPI(pageIndex, dpi, ImageType.RGB);
+
+                    String imageFilename = String.format("page_%03d.png", pageIndex + 1);
+                    Path imagePath = tempDir.resolve(imageFilename);
+
+                    ImageIO.write(image, "PNG", imagePath.toFile());
+                    generatedImages.add(imagePath);
+
+                } catch (IOException e) {
+                    log.warn("Error processing page {}: {}", pageIndex + 1, e.getMessage());
+                } catch (OutOfMemoryError e) {
+                    throw ExceptionUtils.createOutOfMemoryDpiException(pageIndex + 1, dpi, e);
+                } catch (NegativeArraySizeException e) {
+                    throw ExceptionUtils.createOutOfMemoryDpiException(pageIndex + 1, dpi, e);
+                }
+            }
+
+            if (generatedImages.isEmpty()) {
+                throw new IOException("Failed to render any pages to images for CBR conversion");
+            }
+
+            return createRarArchive(tempDir, generatedImages);
+        } finally {
+            cleanupTempFiles(generatedImages, tempDir);
+        }
+    }
+
+    private static byte[] createRarArchive(Path tempDir, List<Path> images) throws IOException {
+        List<String> command = new ArrayList<>();
+        command.add("rar");
+        command.add("a");
+        command.add("-m5");
+        command.add("-ep1");
+
+        Path rarFile = tempDir.resolve("output.cbr");
+        command.add(rarFile.getFileName().toString());
+
+        for (Path image : images) {
+            command.add(image.getFileName().toString());
+        }
+
+        ProcessExecutor executor =
+                ProcessExecutor.getInstance(ProcessExecutor.Processes.INSTALL_APP);
+        try {
+            ProcessExecutorResult result =
+                    executor.runCommandWithOutputHandling(command, tempDir.toFile());
+            if (result.getRc() != 0) {
+                throw new IOException("RAR command failed: " + result.getMessages());
+            }
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new IOException("RAR command interrupted", e);
+        }
+
+        if (!Files.exists(rarFile)) {
+            throw new IOException("RAR file was not created");
+        }
+
+        try (FileInputStream fis = new FileInputStream(rarFile.toFile());
+                ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
+            fis.transferTo(baos);
+            return baos.toByteArray();
+        }
+    }
+
+    private static void cleanupTempFiles(List<Path> images, Path tempDir) {
+        for (Path image : images) {
+            try {
+                Files.deleteIfExists(image);
+            } catch (IOException e) {
+                log.warn("Failed to delete temp image file {}: {}", image, e.getMessage());
+            }
+        }
+        if (tempDir != null) {
+            try (var paths = Files.walk(tempDir)) {
+                paths.sorted(Comparator.reverseOrder())
+                        .forEach(
+                                path -> {
+                                    try {
+                                        Files.deleteIfExists(path);
+                                    } catch (IOException e) {
+                                        log.warn(
+                                                "Failed to delete temp path {}: {}",
+                                                path,
+                                                e.getMessage());
+                                    }
+                                });
+            } catch (IOException e) {
+                log.warn("Failed to clean up temp directory {}: {}", tempDir, e.getMessage());
+            }
+        }
+    }
+
+    public static boolean isPdfFile(MultipartFile file) {
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            return false;
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        return "pdf".equals(extension);
+    }
+}

app/common/src/main/java/stirling/software/common/util/PdfToCbzUtils.java

@@ -0,0 +1,99 @@
+package stirling.software.common.util;
+
+import java.awt.image.BufferedImage;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipOutputStream;
+
+import javax.imageio.ImageIO;
+
+import org.apache.commons.io.FilenameUtils;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.rendering.ImageType;
+import org.apache.pdfbox.rendering.PDFRenderer;
+import org.springframework.web.multipart.MultipartFile;
+
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.common.service.CustomPDFDocumentFactory;
+
+@Slf4j
+public class PdfToCbzUtils {
+
+    public static byte[] convertPdfToCbz(
+            MultipartFile pdfFile, int dpi, CustomPDFDocumentFactory pdfDocumentFactory)
+            throws IOException {
+
+        validatePdfFile(pdfFile);
+
+        try (PDDocument document = pdfDocumentFactory.load(pdfFile)) {
+            if (document.getNumberOfPages() == 0) {
+                throw new IllegalArgumentException("PDF file contains no pages");
+            }
+
+            return createCbzFromPdf(document, dpi);
+        }
+    }
+
+    private static void validatePdfFile(MultipartFile file) {
+        if (file == null || file.isEmpty()) {
+            throw new IllegalArgumentException("File cannot be null or empty");
+        }
+
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            throw new IllegalArgumentException("File must have a name");
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        if (!"pdf".equals(extension)) {
+            throw new IllegalArgumentException("File must be a PDF");
+        }
+    }
+
+    private static byte[] createCbzFromPdf(PDDocument document, int dpi) throws IOException {
+        PDFRenderer pdfRenderer = new PDFRenderer(document);
+
+        try (ByteArrayOutputStream cbzOutputStream = new ByteArrayOutputStream();
+                ZipOutputStream zipOut = new ZipOutputStream(cbzOutputStream)) {
+
+            int totalPages = document.getNumberOfPages();
+
+            for (int pageIndex = 0; pageIndex < totalPages; pageIndex++) {
+                try {
+                    BufferedImage image =
+                            pdfRenderer.renderImageWithDPI(pageIndex, dpi, ImageType.RGB);
+
+                    String imageFilename = String.format("page_%03d.png", pageIndex + 1);
+
+                    ZipEntry zipEntry = new ZipEntry(imageFilename);
+                    zipOut.putNextEntry(zipEntry);
+
+                    ImageIO.write(image, "PNG", zipOut);
+                    zipOut.closeEntry();
+
+                } catch (IOException e) {
+                    log.warn("Error processing page {}: {}", pageIndex + 1, e.getMessage());
+                } catch (OutOfMemoryError e) {
+                    throw ExceptionUtils.createOutOfMemoryDpiException(pageIndex + 1, dpi, e);
+                } catch (NegativeArraySizeException e) {
+                    throw ExceptionUtils.createOutOfMemoryDpiException(pageIndex + 1, dpi, e);
+                }
+            }
+
+            zipOut.finish();
+            return cbzOutputStream.toByteArray();
+        }
+    }
+
+    public static boolean isPdfFile(MultipartFile file) {
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            return false;
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        return "pdf".equals(extension);
+    }
+}

app/common/src/main/java/stirling/software/common/util/PdfUtils.java

@@ -8,6 +8,8 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
 
@@ -29,19 +31,25 @@ import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
 import org.apache.pdfbox.rendering.ImageType;
 import org.apache.pdfbox.rendering.PDFRenderer;
 import org.apache.pdfbox.text.PDFTextStripper;
+import org.springframework.http.MediaType;
 import org.springframework.web.multipart.MultipartFile;
 
 import io.github.pixee.security.Filenames;
 
+import lombok.experimental.UtilityClass;
 import lombok.extern.slf4j.Slf4j;
 
 import stirling.software.common.model.ApplicationProperties;
 import stirling.software.common.service.CustomPDFDocumentFactory;
 
 @Slf4j
+@UtilityClass
 public class PdfUtils {
 
-    public static PDRectangle textToPageSize(String size) {
+    private final RegexPatternUtils patternCache = RegexPatternUtils.getInstance();
+
+    public PDRectangle textToPageSize(String size) {
+
         switch (size.toUpperCase()) {
             case "A0" -> {
                 return PDRectangle.A0;
@@ -74,7 +82,7 @@ public class PdfUtils {
         }
     }
 
-    public static List<RenderedImage> getAllImages(PDResources resources) throws IOException {
+    public List<RenderedImage> getAllImages(PDResources resources) throws IOException {
         List<RenderedImage> images = new ArrayList<>();
 
         for (COSName name : resources.getXObjectNames()) {
@@ -91,7 +99,7 @@ public class PdfUtils {
         return images;
     }
 
-    public static boolean hasImages(PDDocument document, String pagesToCheck) throws IOException {
+    public boolean hasImages(PDDocument document, String pagesToCheck) throws IOException {
         String[] pageOrderArr = pagesToCheck.split(",");
         List<Integer> pageList =
                 GeneralUtils.parsePageList(pageOrderArr, document.getNumberOfPages());
@@ -106,7 +114,7 @@ public class PdfUtils {
         return false;
     }
 
-    public static boolean hasText(PDDocument document, String pageNumbersToCheck, String phrase)
+    public boolean hasText(PDDocument document, String pageNumbersToCheck, String phrase)
             throws IOException {
         String[] pageOrderArr = pageNumbersToCheck.split(",");
         List<Integer> pageList =
@@ -122,11 +130,11 @@ public class PdfUtils {
         return false;
     }
 
-    public static boolean hasImagesOnPage(PDPage page) throws IOException {
-        return getAllImages(page.getResources()).size() > 0;
+    public boolean hasImagesOnPage(PDPage page) throws IOException {
+        return !getAllImages(page.getResources()).isEmpty();
     }
 
-    public static boolean hasTextOnPage(PDPage page, String phrase) throws IOException {
+    public boolean hasTextOnPage(PDPage page, String phrase) throws IOException {
         PDFTextStripper textStripper = new PDFTextStripper();
         PDDocument tempDoc = new PDDocument();
         tempDoc.addPage(page);
@@ -135,14 +143,15 @@ public class PdfUtils {
         return pageText.contains(phrase);
     }
 
-    public static byte[] convertFromPdf(
+    public byte[] convertFromPdf(
             CustomPDFDocumentFactory pdfDocumentFactory,
             byte[] inputStream,
             String imageType,
             ImageType colorType,
             boolean singleImage,
             int DPI,
-            String filename)
+            String filename,
+            boolean includeAnnotations)
             throws IOException, Exception {
 
         // Validate and limit DPI to prevent excessive memory usage
@@ -155,7 +164,8 @@ public class PdfUtils {
         if (DPI > maxSafeDpi) {
             throw ExceptionUtils.createIllegalArgumentException(
                     "error.dpiExceedsLimit",
-                    "DPI value {0} exceeds maximum safe limit of {1}. High DPI values can cause memory issues and crashes. Please use a lower DPI value.",
+                    "DPI value {0} exceeds maximum safe limit of {1}. High DPI values can cause"
+                            + " memory issues and crashes. Please use a lower DPI value.",
                     DPI,
                     maxSafeDpi);
         }
@@ -163,6 +173,9 @@ public class PdfUtils {
         try (PDDocument document = pdfDocumentFactory.load(inputStream)) {
             PDFRenderer pdfRenderer = new PDFRenderer(document);
             pdfRenderer.setSubsamplingAllowed(true);
+            if (!includeAnnotations) {
+                pdfRenderer.setAnnotationsFilter(annotation -> false);
+            }
             int pageCount = document.getNumberOfPages();
 
             // Create a ByteArrayOutputStream to save the image(s) to
@@ -192,11 +205,17 @@ public class PdfUtils {
                                                 .contains("Maximum size of image exceeded")) {
                                     throw ExceptionUtils.createIllegalArgumentException(
                                             "error.pageTooBigForDpi",
-                                            "PDF page {0} is too large to render at {1} DPI. Please try a lower DPI value (recommended: 150 or less).",
+                                            "PDF page {0} is too large to render at {1} DPI. Please"
+                                                    + " try a lower DPI value (recommended: 150 or"
+                                                    + " less).",
                                             i + 1,
                                             DPI);
                                 }
                                 throw e;
+                            } catch (OutOfMemoryError e) {
+                                throw ExceptionUtils.createOutOfMemoryDpiException(i + 1, DPI, e);
+                            } catch (NegativeArraySizeException e) {
+                                throw ExceptionUtils.createOutOfMemoryDpiException(i + 1, DPI, e);
                             }
                             writer.writeToSequence(new IIOImage(image, null, null), param);
                         }
@@ -237,11 +256,18 @@ public class PdfUtils {
                                                 .contains("Maximum size of image exceeded")) {
                                     throw ExceptionUtils.createIllegalArgumentException(
                                             "error.pageTooBigExceedsArray",
-                                            "PDF page {0} is too large to render at {1} DPI. The resulting image would exceed Java's maximum array size. Please try a lower DPI value (recommended: 150 or less).",
+                                            "PDF page {0} is too large to render at {1} DPI. The"
+                                                    + " resulting image would exceed Java's maximum"
+                                                    + " array size. Please try a lower DPI value"
+                                                    + " (recommended: 150 or less).",
                                             i + 1,
                                             DPI);
                                 }
                                 throw e;
+                            } catch (OutOfMemoryError e) {
+                                throw ExceptionUtils.createOutOfMemoryDpiException(i + 1, DPI, e);
+                            } catch (NegativeArraySizeException e) {
+                                throw ExceptionUtils.createOutOfMemoryDpiException(i + 1, DPI, e);
                             }
                             pdfSizeImageIndex = i;
                             dimension =
@@ -278,11 +304,17 @@ public class PdfUtils {
                                                 .contains("Maximum size of image exceeded")) {
                                     throw ExceptionUtils.createIllegalArgumentException(
                                             "error.pageTooBigForDpi",
-                                            "PDF page {0} is too large to render at {1} DPI. Please try a lower DPI value (recommended: 150 or less).",
+                                            "PDF page {0} is too large to render at {1} DPI. Please"
+                                                    + " try a lower DPI value (recommended: 150 or"
+                                                    + " less).",
                                             i + 1,
                                             DPI);
                                 }
                                 throw e;
+                            } catch (OutOfMemoryError e) {
+                                throw ExceptionUtils.createOutOfMemoryDpiException(i + 1, DPI, e);
+                            } catch (NegativeArraySizeException e) {
+                                throw ExceptionUtils.createOutOfMemoryDpiException(i + 1, DPI, e);
                             }
                         }
 
@@ -311,11 +343,16 @@ public class PdfUtils {
                                     && e.getMessage().contains("Maximum size of image exceeded")) {
                                 throw ExceptionUtils.createIllegalArgumentException(
                                         "error.pageTooBigForDpi",
-                                        "PDF page {0} is too large to render at {1} DPI. Please try a lower DPI value (recommended: 150 or less).",
+                                        "PDF page {0} is too large to render at {1} DPI. Please try"
+                                                + " a lower DPI value (recommended: 150 or less).",
                                         i + 1,
                                         DPI);
                             }
                             throw e;
+                        } catch (OutOfMemoryError e) {
+                            throw ExceptionUtils.createOutOfMemoryDpiException(i + 1, DPI, e);
+                        } catch (NegativeArraySizeException e) {
+                            throw ExceptionUtils.createOutOfMemoryDpiException(i + 1, DPI, e);
                         }
                         try (ByteArrayOutputStream baosImage = new ByteArrayOutputStream()) {
                             ImageIO.write(image, imageType, baosImage);
@@ -349,23 +386,38 @@ public class PdfUtils {
      * @return converted document to PDF-Image
      * @throws IOException if conversion fails
      */
-    public static PDDocument convertPdfToPdfImage(PDDocument document) throws IOException {
+    public PDDocument convertPdfToPdfImage(PDDocument document) throws IOException {
         PDDocument imageDocument = new PDDocument();
         PDFRenderer pdfRenderer = new PDFRenderer(document);
         pdfRenderer.setSubsamplingAllowed(true);
         for (int page = 0; page < document.getNumberOfPages(); ++page) {
             BufferedImage bim;
+
+            // Use global maximum DPI setting, fallback to 300 if not set
+            int renderDpi = 300; // Default fallback
+            ApplicationProperties properties =
+                    ApplicationContextProvider.getBean(ApplicationProperties.class);
+            if (properties != null && properties.getSystem() != null) {
+                renderDpi = properties.getSystem().getMaxDPI();
+            }
+
             try {
-                bim = pdfRenderer.renderImageWithDPI(page, 300, ImageType.RGB);
+                bim = pdfRenderer.renderImageWithDPI(page, renderDpi, ImageType.RGB);
             } catch (IllegalArgumentException e) {
                 if (e.getMessage() != null
                         && e.getMessage().contains("Maximum size of image exceeded")) {
                     throw ExceptionUtils.createIllegalArgumentException(
                             "error.pageTooBigFor300Dpi",
-                            "PDF page {0} is too large to render at 300 DPI. The resulting image would exceed Java's maximum array size. Please use a lower DPI value for PDF-to-image conversion.",
+                            "PDF page {0} is too large to render at 300 DPI. The resulting image"
+                                    + " would exceed Java's maximum array size. Please use a lower DPI"
+                                    + " value for PDF-to-image conversion.",
                             page + 1);
                 }
                 throw e;
+            } catch (OutOfMemoryError e) {
+                throw ExceptionUtils.createOutOfMemoryDpiException(page + 1, 300, e);
+            } catch (NegativeArraySizeException e) {
+                throw ExceptionUtils.createOutOfMemoryDpiException(page + 1, 300, e);
             }
             PDPage originalPage = document.getPage(page);
 
@@ -383,8 +435,7 @@ public class PdfUtils {
         return imageDocument;
     }
 
-    private static BufferedImage prepareImageForPdfToImage(
-            int maxWidth, int height, String imageType) {
+    private BufferedImage prepareImageForPdfToImage(int maxWidth, int height, String imageType) {
         BufferedImage combined;
         if ("png".equalsIgnoreCase(imageType)) {
             combined = new BufferedImage(maxWidth, height, BufferedImage.TYPE_INT_ARGB);
@@ -400,7 +451,7 @@ public class PdfUtils {
         return combined;
     }
 
-    public static byte[] imageToPdf(
+    public byte[] imageToPdf(
             MultipartFile[] files,
             String fitOption,
             boolean autoRotate,
@@ -431,7 +482,7 @@ public class PdfUtils {
                             ImageProcessingUtils.convertColorType(image, colorType);
                     // Use JPEGFactory if it's JPEG since JPEG is lossy
                     PDImageXObject pdImage =
-                            (contentType != null && "image/jpeg".equals(contentType))
+                            (contentType != null && MediaType.IMAGE_JPEG_VALUE.equals(contentType))
                                     ? JPEGFactory.createFromImage(doc, convertedImage)
                                     : LosslessFactory.createFromImage(doc, convertedImage);
                     addImageToDocument(doc, pdImage, fitOption, autoRotate);
@@ -444,7 +495,7 @@ public class PdfUtils {
         }
     }
 
-    public static void addImageToDocument(
+    public void addImageToDocument(
             PDDocument doc, PDImageXObject image, String fitOption, boolean autoRotate)
             throws IOException {
         boolean imageIsLandscape = image.getWidth() > image.getHeight();
@@ -494,7 +545,7 @@ public class PdfUtils {
         }
     }
 
-    public static byte[] overlayImage(
+    public byte[] overlayImage(
             CustomPDFDocumentFactory pdfDocumentFactory,
             byte[] pdfBytes,
             byte[] imageBytes,
@@ -536,13 +587,16 @@ public class PdfUtils {
     public boolean containsTextInFile(PDDocument pdfDocument, String text, String pagesToCheck)
             throws IOException {
         PDFTextStripper textStripper = new PDFTextStripper();
-        String pdfText = "";
+        StringBuilder pdfText = new StringBuilder();
 
         if (pagesToCheck == null || "all".equals(pagesToCheck)) {
-            pdfText = textStripper.getText(pdfDocument);
+            pdfText = new StringBuilder(textStripper.getText(pdfDocument));
         } else {
-            // remove whitespaces
-            pagesToCheck = pagesToCheck.replaceAll("\\s+", "");
+            // remove whitespaces using cached pattern
+            Pattern whitespacePattern =
+                    patternCache.getPattern(RegexPatternUtils.getWhitespaceRegex());
+            Matcher whitespaceMatcher = whitespacePattern.matcher(pagesToCheck);
+            pagesToCheck = whitespaceMatcher.replaceAll("");
 
             String[] splitPoints = pagesToCheck.split(",");
             for (String splitPoint : splitPoints) {
@@ -555,21 +609,21 @@ public class PdfUtils {
                     for (int i = startPage; i <= endPage; i++) {
                         textStripper.setStartPage(i);
                         textStripper.setEndPage(i);
-                        pdfText += textStripper.getText(pdfDocument);
+                        pdfText.append(textStripper.getText(pdfDocument));
                     }
                 } else {
                     // Handle individual page
                     int page = Integer.parseInt(splitPoint);
                     textStripper.setStartPage(page);
                     textStripper.setEndPage(page);
-                    pdfText += textStripper.getText(pdfDocument);
+                    pdfText.append(textStripper.getText(pdfDocument));
                 }
             }
         }
 
         pdfDocument.close();
 
-        return pdfText.contains(text);
+        return pdfText.toString().contains(text);
     }
 
     public boolean pageCount(PDDocument pdfDocument, int pageCount, String comparator)
@@ -577,16 +631,13 @@ public class PdfUtils {
         int actualPageCount = pdfDocument.getNumberOfPages();
         pdfDocument.close();
 
-        switch (comparator.toLowerCase()) {
-            case "greater":
-                return actualPageCount > pageCount;
-            case "equal":
-                return actualPageCount == pageCount;
-            case "less":
-                return actualPageCount < pageCount;
-            default:
-                throw ExceptionUtils.createInvalidArgumentException("comparator", comparator);
-        }
+        return switch (comparator.toLowerCase()) {
+            case "greater" -> actualPageCount > pageCount;
+            case "equal" -> actualPageCount == pageCount;
+            case "less" -> actualPageCount < pageCount;
+            default ->
+                    throw ExceptionUtils.createInvalidArgumentException("comparator", comparator);
+        };
     }
 
     public boolean pageSize(PDDocument pdfDocument, String expectedPageSize) throws IOException {

app/common/src/main/java/stirling/software/common/util/ProcessExecutor.java

@@ -15,6 +15,8 @@ import java.util.concurrent.TimeUnit;
 
 import io.github.pixee.security.BoundedLineReader;
 
+import lombok.Getter;
+import lombok.Setter;
 import lombok.extern.slf4j.Slf4j;
 
 import stirling.software.common.model.ApplicationProperties;
@@ -167,7 +169,7 @@ public class ProcessExecutor {
         semaphore.acquire();
         try {
 
-            log.info("Running command: " + String.join(" ", command));
+            log.info("Running command: {}", String.join(" ", command));
             ProcessBuilder processBuilder = new ProcessBuilder(command);
 
             // Use the working directory if it's set
@@ -252,7 +254,7 @@ public class ProcessExecutor {
                 String outputMessage = String.join("\n", outputLines);
                 messages += outputMessage;
                 if (!liveUpdates) {
-                    log.info("Command output:\n" + outputMessage);
+                    log.info("Command output:\n{}", outputMessage);
                 }
             }
 
@@ -260,7 +262,7 @@ public class ProcessExecutor {
                 String errorMessage = String.join("\n", errorLines);
                 messages += errorMessage;
                 if (!liveUpdates) {
-                    log.warn("Command error output:\n" + errorMessage);
+                    log.warn("Command error output:\n{}", errorMessage);
                 }
                 if (exitCode != 0) {
                     if (isQpdf && exitCode == 3) {
@@ -306,6 +308,8 @@ public class ProcessExecutor {
         CFF_CONVERTER
     }
 
+    @Setter
+    @Getter
     public class ProcessExecutorResult {
         int rc;
         String messages;
@@ -314,21 +318,5 @@ public class ProcessExecutor {
             this.rc = rc;
             this.messages = messages;
         }
-
-        public int getRc() {
-            return rc;
-        }
-
-        public void setRc(int rc) {
-            this.rc = rc;
-        }
-
-        public String getMessages() {
-            return messages;
-        }
-
-        public void setMessages(String messages) {
-            this.messages = messages;
-        }
     }
 }

app/common/src/main/java/stirling/software/common/util/RegexPatternUtils.java

@@ -0,0 +1,524 @@
+package stirling.software.common.util;
+
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public final class RegexPatternUtils {
+
+    private static final RegexPatternUtils INSTANCE = new RegexPatternUtils();
+    private final ConcurrentHashMap<PatternKey, Pattern> patternCache = new ConcurrentHashMap<>();
+
+    private static final String WHITESPACE_REGEX = "\\s++";
+    private static final String EXTENSION_REGEX = "\\.(?:[^.]*+)?$";
+
+    private RegexPatternUtils() {
+        super();
+        // Initialize with commonly used patterns for immediate availability
+        precompileCommonPatterns();
+    }
+
+    /**
+     * Get the singleton instance of the pattern cache.
+     *
+     * @return the singleton RegexPatternCache instance
+     */
+    public static RegexPatternUtils getInstance() {
+        return INSTANCE;
+    }
+
+    /**
+     * Get a compiled pattern from cache, compiling and caching if not present.
+     *
+     * <p>This method is thread-safe and uses lazy initialization. Multiple threads calling with the
+     * same regex will result in only one compilation, with all threads receiving the same cached
+     * Pattern instance.
+     *
+     * <p>Performance: first call compiles and caches (expensive), subsequent calls return cached
+     * pattern (fast O(1) lookup).
+     *
+     * @param regex the regular expression string to compile
+     * @return compiled Pattern object, never null
+     * @throws PatternSyntaxException if the regex syntax is invalid
+     * @throws IllegalArgumentException if regex is null
+     */
+    public Pattern getPattern(String regex) {
+        if (regex == null) {
+            throw new IllegalArgumentException("Regex pattern cannot be null");
+        }
+
+        return patternCache.computeIfAbsent(new PatternKey(regex, 0), this::compilePattern);
+    }
+
+    /**
+     * Get a compiled pattern with flags.
+     *
+     * <p>Patterns with different flags are cached separately using a composite key. Common flags
+     * include:
+     *
+     * <ul>
+     *   <li>{@link Pattern#CASE_INSENSITIVE} - ignore case differences
+     *   <li>{@link Pattern#MULTILINE} - ^ and $ match line boundaries
+     *   <li>{@link Pattern#DOTALL} - . matches any character including newlines
+     * </ul>
+     *
+     * @param regex the regular expression string
+     * @param flags pattern flags (e.g., Pattern.CASE_INSENSITIVE)
+     * @return compiled Pattern object with specified flags
+     * @throws PatternSyntaxException if the regex syntax is invalid
+     * @throws IllegalArgumentException if regex is null
+     */
+    public Pattern getPattern(String regex, int flags) {
+        if (regex == null) {
+            throw new IllegalArgumentException("Regex pattern cannot be null");
+        }
+
+        return patternCache.computeIfAbsent(new PatternKey(regex, flags), this::compilePattern);
+    }
+
+    /**
+     * Check if a pattern is already cached.
+     *
+     * @param regex the regular expression string
+     * @return true if pattern is cached, false otherwise
+     */
+    public boolean isCached(String regex) {
+        return isCached(regex, 0);
+    }
+
+    /**
+     * Check if a pattern with flags is already cached.
+     *
+     * @param regex the regular expression string
+     * @param flags pattern flags
+     * @return true if pattern is cached, false otherwise
+     */
+    public boolean isCached(String regex, int flags) {
+        return regex != null && patternCache.containsKey(new PatternKey(regex, flags));
+    }
+
+    /**
+     * Get current cache size (number of cached patterns). Useful for monitoring and debugging.
+     *
+     * @return number of patterns currently cached
+     */
+    public int getCacheSize() {
+        return patternCache.size();
+    }
+
+    /**
+     * Clear all cached patterns. Use sparingly as it forces recompilation of all patterns. Mainly
+     * useful for testing or memory cleanup in long-running applications.
+     */
+    public void clearCache() {
+        patternCache.clear();
+        log.debug("Regex pattern cache cleared");
+    }
+
+    /**
+     * Remove a specific pattern from cache.
+     *
+     * @param regex the regular expression string to remove
+     * @return true if pattern was cached and removed, false otherwise
+     */
+    public boolean removeFromCache(String regex) {
+        return removeFromCache(regex, 0);
+    }
+
+    /**
+     * Remove a specific pattern with flags from cache.
+     *
+     * @param regex the regular expression string to remove
+     * @param flags pattern flags
+     * @return true if pattern was cached and removed, false otherwise
+     */
+    public boolean removeFromCache(String regex, int flags) {
+        if (regex == null) {
+            return false;
+        }
+        PatternKey key = new PatternKey(regex, flags);
+        boolean removed = patternCache.remove(key) != null;
+        if (removed) {
+            log.debug("Removed regex pattern from cache: {} (flags: {})", regex, flags);
+        }
+        return removed;
+    }
+
+    /**
+     * Internal method to compile a pattern and handle errors consistently.
+     *
+     * @return compiled Pattern
+     * @throws PatternSyntaxException if regex is invalid
+     */
+    private Pattern compilePattern(PatternKey key) {
+        String regex = key.regex;
+        int flags = key.flags;
+
+        try {
+            Pattern pattern = Pattern.compile(regex, flags);
+            log.trace("Compiled and cached regex pattern with flags {}: {}", flags, regex);
+            return pattern;
+        } catch (PatternSyntaxException e) {
+            log.error(
+                    "Invalid regex pattern: '{}' with flags {} - {}", regex, flags, e.getMessage());
+            throw e;
+        }
+    }
+
+    public static String getWhitespaceRegex() {
+        return WHITESPACE_REGEX;
+    }
+
+    /** Creates a case-insensitive pattern for text searching */
+    public Pattern createSearchPattern(String regex, boolean caseInsensitive) {
+        int flags = caseInsensitive ? (Pattern.CASE_INSENSITIVE | Pattern.UNICODE_CASE) : 0;
+        return getPattern(regex, flags);
+    }
+
+    /** Pattern for matching trailing slashes (e.g., "/path/to/dir///") */
+    public Pattern getTrailingSlashesPattern() {
+        return getPattern("/+$");
+    }
+
+    /** Pattern for removing drive letters from paths */
+    public Pattern getDriveLetterPattern() {
+        return getPattern("^[a-zA-Z]:[\\\\/]+");
+    }
+
+    /** Pattern for removing leading slashes from paths */
+    public Pattern getLeadingSlashesPattern() {
+        return getPattern("^[\\\\/]+");
+    }
+
+    /** Pattern for matching backslashes */
+    public Pattern getBackslashPattern() {
+        return getPattern("\\\\");
+    }
+
+    /** Pattern for sanitizing filenames by removing problematic characters */
+    public Pattern getSafeFilenamePattern() {
+        return getPattern("[/\\\\?%*:|\"<>]");
+    }
+
+    /** Pattern for sanitizing filenames (keeps only alphanumeric) */
+    public Pattern getFilenameSafePattern() {
+        return getPattern("[^a-zA-Z0-9]");
+    }
+
+    /**
+     * Pattern for replacing non-alphanumeric characters with underscore (explicit underscore
+     * variant)
+     */
+    public Pattern getNonAlnumUnderscorePattern() {
+        return getPattern("[^A-Za-z0-9_]");
+    }
+
+    /** Pattern for collapsing multiple underscores */
+    public Pattern getMultipleUnderscoresPattern() {
+        return getPattern("_+");
+    }
+
+    /** Pattern for trimming leading underscores */
+    public Pattern getLeadingUnderscoresPattern() {
+        return getPattern("^_+");
+    }
+
+    /** Pattern for trimming trailing underscores */
+    public Pattern getTrailingUnderscoresPattern() {
+        return getPattern("_+$");
+    }
+
+    /** Pattern for matching upload/download paths (case insensitive) */
+    public Pattern getUploadDownloadPathPattern() {
+        return getPattern("(?i).*/(upload|download)/.*");
+    }
+
+    /** Pattern for matching one or more whitespace characters */
+    public Pattern getWhitespacePattern() {
+        return getPattern("\\s+");
+    }
+
+    /** Pattern for matching newlines (Windows and Unix style) */
+    public Pattern getNewlinesPattern() {
+        return getPattern("\\r?\\n");
+    }
+
+    /** Pattern for splitting on newlines (Windows and Unix style) */
+    public Pattern getNewlineSplitPattern() {
+        return getPattern("\\r?\\n");
+    }
+
+    /** Pattern for splitting text into words */
+    public Pattern getWordSplitPattern() {
+        return getPattern("\\s+");
+    }
+
+    /** Pattern for removing carriage returns */
+    public Pattern getCarriageReturnPattern() {
+        return getPattern("\\r");
+    }
+
+    /** Pattern for matching newline characters */
+    public Pattern getNewlineCharsPattern() {
+        return getPattern("[\n\r]");
+    }
+
+    /** Pattern for multi-format newline splitting (Windows, Mac, Unix) */
+    public Pattern getMultiFormatNewlinePattern() {
+        return getPattern("\r\n|\r|\n");
+    }
+
+    /** Pattern for encoded payload newline removal */
+    public Pattern getEncodedPayloadNewlinePattern() {
+        return getPattern("\\r?\\n");
+    }
+
+    /** Pattern for escaped newlines in watermark text */
+    public Pattern getEscapedNewlinePattern() {
+        return getPattern("\\\\n");
+    }
+
+    /** Pattern for input sanitization (allows only alphanumeric and spaces) */
+    public Pattern getInputSanitizePattern() {
+        return getPattern("[^a-zA-Z0-9 ]");
+    }
+
+    /** Pattern for removing angle brackets */
+    public Pattern getAngleBracketsPattern() {
+        return getPattern("[<>]");
+    }
+
+    /** Pattern for removing leading and trailing quotes */
+    public Pattern getQuotesRemovalPattern() {
+        return getPattern("^\"|\"$");
+    }
+
+    /** Pattern for plus signs (URL encoding replacement) */
+    public Pattern getPlusSignPattern() {
+        return getPattern("\\+");
+    }
+
+    /** Pattern for username validation */
+    public Pattern getUsernameValidationPattern() {
+        return getPattern("^[a-zA-Z0-9](?!.*[-@._+]{2,})[a-zA-Z0-9@._+-]{1,48}[a-zA-Z0-9]$");
+    }
+
+    public static String getExtensionRegex() {
+        return EXTENSION_REGEX;
+    }
+
+    /** Pattern for extracting non-numeric characters */
+    public Pattern getNumericExtractionPattern() {
+        return getPattern("\\D");
+    }
+
+    /** Pattern for removing non-digit/dot characters (for timeout parsing) */
+    public Pattern getNonDigitDotPattern() {
+        return getPattern("[^\\d.]");
+    }
+
+    /** Pattern for matching digit/dot characters (for timeout parsing) */
+    public Pattern getDigitDotPattern() {
+        return getPattern("[\\d.]");
+    }
+
+    /** Pattern for detecting strings containing digits */
+    public Pattern getContainsDigitsPattern() {
+        return getPattern(".*\\d+.*");
+    }
+
+    /** Pattern for matching 1-3 digit numbers */
+    public Pattern getNumberRangePattern() {
+        return getPattern("[1-9][0-9]{0,2}");
+    }
+
+    /** Pattern for validating mathematical expressions */
+    public Pattern getMathExpressionPattern() {
+        return getPattern("[0-9n+\\-*/() ]+");
+    }
+
+    /** Pattern for adding multiplication between numbers and 'n' */
+    public Pattern getNumberBeforeNPattern() {
+        return getPattern("(\\d)n");
+    }
+
+    /** Pattern for detecting consecutive 'n' characters */
+    public Pattern getConsecutiveNPattern() {
+        return getPattern(".*n{2,}.*");
+    }
+
+    /** Pattern for replacing consecutive 'n' characters */
+    public Pattern getConsecutiveNReplacementPattern() {
+        return getPattern("(?<!n)n{2}");
+    }
+
+    /** Pattern for validating HTTP/HTTPS URLs */
+    public Pattern getHttpUrlPattern() {
+        return getPattern("^https?://.*");
+    }
+
+    /** Pattern for matching URLs in text for link creation */
+    public Pattern getUrlLinkPattern() {
+        return getPattern("(https?://[\\w\\-._~:/?#\\[\\]@!$&'()*+,;=%]+)");
+    }
+
+    /** Pattern for matching email addresses in text for link creation */
+    public Pattern getEmailLinkPattern() {
+        return getPattern("([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,63})");
+    }
+
+    /** Pattern for removing script tags from HTML */
+    public Pattern getScriptTagPattern() {
+        return getPattern("(?i)<script[^>]*>.*?</script>");
+    }
+
+    /** Pattern for removing style tags from HTML */
+    public Pattern getStyleTagPattern() {
+        return getPattern("(?i)<style[^>]*>.*?</style>");
+    }
+
+    /** Pattern for removing fixed position CSS */
+    public Pattern getFixedPositionCssPattern() {
+        return getPattern("(?i)\\s*position\\s*:\\s*fixed[^;]*;?");
+    }
+
+    /** Pattern for removing absolute position CSS */
+    public Pattern getAbsolutePositionCssPattern() {
+        return getPattern("(?i)\\s*position\\s*:\\s*absolute[^;]*;?");
+    }
+
+    /** Pattern for matching size unit suffixes (KB, MB, GB, etc.) */
+    public Pattern getSizeUnitPattern() {
+        return getPattern("[KMGkmg][Bb]");
+    }
+
+    /** Pattern for system temp file type 1 */
+    public Pattern getSystemTempFile1Pattern() {
+        return getPattern("lu\\d+[a-z0-9]*\\.tmp");
+    }
+
+    /** Pattern for system temp file type 2 (OCR processes) */
+    public Pattern getSystemTempFile2Pattern() {
+        return getPattern("ocr_process\\d+");
+    }
+
+    /** Pattern for splitting on whitespace and parentheses */
+    public Pattern getWhitespaceParenthesesSplitPattern() {
+        return getPattern("[\\s\\(\\)]+");
+    }
+
+    /** Pattern for MIME header whitespace cleanup before encoded sequences */
+    public Pattern getMimeHeaderWhitespacePattern() {
+        return getPattern("\\s+(?==\\?)");
+    }
+
+    /** Pattern for font name validation (6 uppercase letters + plus + rest) */
+    public Pattern getFontNamePattern() {
+        return getPattern("^[A-Z]{6}\\+.*");
+    }
+
+    /** Pattern for matching access="readOnly" attribute in XFA XML (with optional whitespace) */
+    public Pattern getAccessReadOnlyPattern() {
+        return getPattern("access\\s*=\\s*\"readOnly\"");
+    }
+
+    /** Pattern for matching MIME encoded-word headers (RFC 2047) Example: =?charset?B?encoded?= */
+    public Pattern getMimeEncodedWordPattern() {
+        return getPattern("=\\?([^?]+)\\?([BbQq])\\?([^?]*)\\?=");
+    }
+
+    /** Pattern for matching inline CID images in HTML (case-insensitive) */
+    public Pattern getInlineCidImagePattern() {
+        return getPattern(
+                "(?i)<img[^>]*\\ssrc\\s*=\\s*['\"]cid:([^'\"]+)['\"][^>]*>",
+                Pattern.CASE_INSENSITIVE);
+    }
+
+    /** Pattern for matching image file extensions (case-insensitive) */
+    public Pattern getImageFilePattern() {
+        return getPattern(".*\\.(jpg|jpeg|png|gif|bmp|webp)$", Pattern.CASE_INSENSITIVE);
+    }
+
+    /** Pattern for matching attachment section headers (case-insensitive) */
+    public Pattern getAttachmentSectionPattern() {
+        return getPattern("attachments\\s*\\(\\d+\\)", Pattern.CASE_INSENSITIVE);
+    }
+
+    /** Pattern for matching filenames in attachment markers */
+    public Pattern getAttachmentFilenamePattern() {
+        return getPattern("@\\s*([^\\s\\(]+(?:\\.[a-zA-Z0-9]+)?)");
+    }
+
+    /** Pattern for matching pdfaid:part attribute in XMP metadata */
+    public Pattern getPdfAidPartPattern() {
+        return getPattern("pdfaid:part[\"\\s]*=[\"\\s]*([0-9]+)");
+    }
+
+    /** Pattern for matching pdfaid:conformance attribute in XMP metadata */
+    public Pattern getPdfAidConformancePattern() {
+        return getPattern("pdfaid:conformance[\"\\s]*=[\"\\s]*([A-Za-z]+)");
+    }
+
+    /** Pattern for matching slash in page mode description */
+    public Pattern getPageModePattern() {
+        return getPattern("/");
+    }
+
+    /**
+     * Pre-compile commonly used patterns for immediate availability. This eliminates first-call
+     * compilation overhead for frequent patterns.
+     */
+    private void precompileCommonPatterns() {
+        getPattern("\\.(?:[^.]*+)?$"); // Extension removal - possessive, optional, anchored
+        getPattern("\\.[^.]+$"); // Simple extension match - anchored
+
+        getPattern("\\s+"); // One or more whitespace
+        getPattern("\\s*"); // Zero or more whitespace
+
+        getPattern("/+$"); // Trailing slashes
+        getPattern("\\D"); // Non-numeric characters
+        getPattern("[/\\\\?%*:|\"<>]"); // Unsafe filename characters
+        getPattern("[^a-zA-Z0-9 ]"); // Input sanitization
+        getPattern("[^a-zA-Z0-9]"); // Filename sanitization
+        // API doc patterns
+        getPattern("Output:(\\w+)"); // precompiled single-escaped for runtime regex \w
+        getPattern("Input:(\\w+)");
+        getPattern("Type:(\\w+)");
+        log.debug("Pre-compiled {} common regex patterns", patternCache.size());
+    }
+
+    /** Pattern for email validation */
+    public Pattern getEmailValidationPattern() {
+        return getPattern(
+                "^(?=.{1,320}$)(?=.{1,64}@)[A-Za-z0-9](?:[A-Za-z0-9_.+-]*[A-Za-z0-9])?@[^-][A-Za-z0-9-]+(?:\\.[A-Za-z0-9-]+)*(?:\\.[A-Za-z]{2,})$");
+    }
+
+    /* Pattern for matching Output:<TYPE> in API descriptions */
+    public Pattern getApiDocOutputTypePattern() {
+        return getPattern("Output:(\\w+)");
+    }
+
+    /* Pattern for matching Input:<TYPE> in API descriptions */
+    public Pattern getApiDocInputTypePattern() {
+        return getPattern("Input:(\\w+)");
+    }
+
+    /**
+     * Pattern for matching Type:<CODE> in API descriptions
+     */
+    public Pattern getApiDocTypePattern() {
+        return getPattern("Type:(\\w+)");
+    }
+
+    /* Pattern for validating file extensions (2-4 alphanumeric, case-insensitive) */
+    public Pattern getFileExtensionValidationPattern() {
+        return getPattern("^[a-zA-Z0-9]{2,4}$", Pattern.CASE_INSENSITIVE);
+    }
+
+    private record PatternKey(String regex, int flags) {
+        // Record automatically provides equals, hashCode, and toString
+    }
+}

app/common/src/main/java/stirling/software/common/util/RequestUriUtils.java

@@ -49,4 +49,35 @@ public class RequestUriUtils {
                 || requestURI.startsWith("/fonts")
                 || requestURI.startsWith("/pdfjs"));
     }
+
+    /**
+     * Checks if the request URI is a public authentication endpoint that doesn't require
+     * authentication. This includes login, signup, OAuth callbacks, and public config endpoints.
+     *
+     * @param requestURI The full request URI
+     * @param contextPath The servlet context path
+     * @return true if the endpoint is public and doesn't require authentication
+     */
+    public static boolean isPublicAuthEndpoint(String requestURI, String contextPath) {
+        // Remove context path from URI to normalize path matching
+        String trimmedUri =
+                requestURI.startsWith(contextPath)
+                        ? requestURI.substring(contextPath.length())
+                        : requestURI;
+
+        // Public auth endpoints that don't require authentication
+        return trimmedUri.startsWith("/login")
+                || trimmedUri.startsWith("/auth/")
+                || trimmedUri.startsWith("/oauth2")
+                || trimmedUri.startsWith("/saml2")
+                || trimmedUri.contains("/login/oauth2/code/") // Spring Security OAuth2 callback
+                || trimmedUri.contains("/oauth2/authorization/") // OAuth2 authorization endpoint
+                || trimmedUri.startsWith("/api/v1/auth/login")
+                || trimmedUri.startsWith("/api/v1/auth/refresh")
+                || trimmedUri.startsWith("/api/v1/auth/logout")
+                || trimmedUri.startsWith("/v1/api-docs")
+                || trimmedUri.startsWith("/api/v1/invite/validate")
+                || trimmedUri.startsWith("/api/v1/invite/accept")
+                || trimmedUri.contains("/v1/api-docs");
+    }
 }

app/common/src/main/java/stirling/software/common/util/TempFile.java

@@ -4,6 +4,7 @@ import java.io.File;
 import java.io.IOException;
 import java.nio.file.Path;
 
+import lombok.Getter;
 import lombok.extern.slf4j.Slf4j;
 
 /**
@@ -14,17 +15,13 @@ import lombok.extern.slf4j.Slf4j;
 public class TempFile implements AutoCloseable {
 
     private final TempFileManager manager;
-    private final File file;
+    @Getter private final File file;
 
     public TempFile(TempFileManager manager, String suffix) throws IOException {
         this.manager = manager;
         this.file = manager.createTempFile(suffix);
     }
 
-    public File getFile() {
-        return file;
-    }
-
     public Path getPath() {
         return file.toPath();
     }

app/common/src/main/java/stirling/software/common/util/TempFileRegistry.java

@@ -13,6 +13,7 @@ import java.util.stream.Collectors;
 
 import org.springframework.stereotype.Component;
 
+import lombok.Getter;
 import lombok.extern.slf4j.Slf4j;
 
 /**
@@ -24,8 +25,22 @@ import lombok.extern.slf4j.Slf4j;
 public class TempFileRegistry {
 
     private final ConcurrentMap<Path, Instant> registeredFiles = new ConcurrentHashMap<>();
+
+    /**
+     * -- GETTER -- Get all registered third-party temporary files.
+     *
+     * @return Set of third-party file paths
+     */
+    @Getter
     private final Set<Path> thirdPartyTempFiles =
             Collections.newSetFromMap(new ConcurrentHashMap<>());
+
+    /**
+     * -- GETTER -- Get all registered temporary directories.
+     *
+     * @return Set of temporary directory paths
+     */
+    @Getter
     private final Set<Path> tempDirectories = Collections.newSetFromMap(new ConcurrentHashMap<>());
 
     /**
@@ -133,24 +148,6 @@ public class TempFileRegistry {
                 .collect(Collectors.toSet());
     }
 
-    /**
-     * Get all registered third-party temporary files.
-     *
-     * @return Set of third-party file paths
-     */
-    public Set<Path> getThirdPartyTempFiles() {
-        return thirdPartyTempFiles;
-    }
-
-    /**
-     * Get all registered temporary directories.
-     *
-     * @return Set of temporary directory paths
-     */
-    public Set<Path> getTempDirectories() {
-        return tempDirectories;
-    }
-
     /**
      * Check if a file is registered in the registry.
      *

app/common/src/main/java/stirling/software/common/util/WebResponseUtils.java

@@ -4,6 +4,8 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
 
 import org.apache.pdfbox.pdmodel.PDDocument;
 import org.springframework.http.HttpHeaders;
@@ -11,9 +13,13 @@ import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.multipart.MultipartFile;
+import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
 import io.github.pixee.security.Filenames;
 
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
 public class WebResponseUtils {
 
     public static ResponseEntity<byte[]> baosToWebResponse(
@@ -44,7 +50,10 @@ public class WebResponseUtils {
         headers.setContentType(mediaType);
         headers.setContentLength(bytes.length);
         String encodedDocName =
-                URLEncoder.encode(docName, StandardCharsets.UTF_8).replaceAll("\\+", "%20");
+                RegexPatternUtils.getInstance()
+                        .getPlusSignPattern()
+                        .matcher(URLEncoder.encode(docName, StandardCharsets.UTF_8))
+                        .replaceAll("%20");
         headers.setContentDispositionFormData("attachment", encodedDocName);
         return new ResponseEntity<>(bytes, headers, HttpStatus.OK);
     }
@@ -64,4 +73,59 @@ public class WebResponseUtils {
 
         return baosToWebResponse(baos, docName);
     }
+
+    /**
+     * Convert a File to a web response (PDF default).
+     *
+     * @param outputTempFile The temporary file to be sent as a response.
+     * @param docName The name of the document.
+     * @return A ResponseEntity containing the file as a resource.
+     */
+    public static ResponseEntity<StreamingResponseBody> pdfFileToWebResponse(
+            TempFile outputTempFile, String docName) throws IOException {
+        return fileToWebResponse(outputTempFile, docName, MediaType.APPLICATION_PDF);
+    }
+
+    /**
+     * Convert a File to a web response (ZIP default).
+     *
+     * @param outputTempFile The temporary file to be sent as a response.
+     * @param docName The name of the document.
+     * @return A ResponseEntity containing the file as a resource.
+     */
+    public static ResponseEntity<StreamingResponseBody> zipFileToWebResponse(
+            TempFile outputTempFile, String docName) throws IOException {
+        return fileToWebResponse(outputTempFile, docName, MediaType.APPLICATION_OCTET_STREAM);
+    }
+
+    /**
+     * Convert a File to a web response with explicit media type (e.g., ZIP).
+     *
+     * @param outputTempFile The temporary file to be sent as a response.
+     * @param docName The name of the document.
+     * @param mediaType The content type to set on the response.
+     * @return A ResponseEntity containing the file as a resource.
+     */
+    public static ResponseEntity<StreamingResponseBody> fileToWebResponse(
+            TempFile outputTempFile, String docName, MediaType mediaType) throws IOException {
+
+        Path path = outputTempFile.getFile().toPath().normalize();
+        long len = Files.size(path);
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(mediaType);
+        headers.setContentLength(len);
+        headers.add(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + docName + "\"");
+
+        StreamingResponseBody body =
+                os -> {
+                    try (os) {
+                        Files.copy(path, os);
+                        os.flush();
+                    } finally {
+                        outputTempFile.close();
+                    }
+                };
+
+        return new ResponseEntity<>(body, headers, HttpStatus.OK);
+    }
 }

app/common/src/main/java/stirling/software/common/util/YamlHelper.java

@@ -10,6 +10,7 @@ import java.util.Arrays;
 import java.util.Deque;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.function.Function;
@@ -135,6 +136,17 @@ public class YamlHelper {
                 } else if ("true".equals(newValue) || "false".equals(newValue)) {
                     newValueNode =
                             new ScalarNode(Tag.BOOL, String.valueOf(newValue), ScalarStyle.PLAIN);
+                } else if (newValue instanceof Map<?, ?> map) {
+                    // Handle Map objects - convert to MappingNode
+                    List<NodeTuple> mapTuples = new ArrayList<>();
+                    for (Map.Entry<?, ?> entry : map.entrySet()) {
+                        ScalarNode mapKeyNode =
+                                new ScalarNode(
+                                        Tag.STR, String.valueOf(entry.getKey()), ScalarStyle.PLAIN);
+                        Node mapValueNode = convertValueToNode(entry.getValue());
+                        mapTuples.add(new NodeTuple(mapKeyNode, mapValueNode));
+                    }
+                    newValueNode = new MappingNode(Tag.MAP, mapTuples, FlowStyle.BLOCK);
                 } else if (newValue instanceof List<?> list) {
                     List<Node> sequenceNodes = new ArrayList<>();
                     for (Object item : list) {
@@ -458,6 +470,43 @@ public class YamlHelper {
         return isInteger(object) || isShort(object) || isByte(object) || isLong(object);
     }
 
+    /**
+     * Converts a Java value to a YAML Node.
+     *
+     * @param value The value to convert.
+     * @return The corresponding YAML Node.
+     */
+    private Node convertValueToNode(Object value) {
+        if (value == null) {
+            return new ScalarNode(Tag.NULL, "null", ScalarStyle.PLAIN);
+        } else if (isAnyInteger(value)) {
+            return new ScalarNode(Tag.INT, String.valueOf(value), ScalarStyle.PLAIN);
+        } else if (isFloat(value)) {
+            Object floatValue = Float.valueOf(String.valueOf(value));
+            return new ScalarNode(Tag.FLOAT, String.valueOf(floatValue), ScalarStyle.PLAIN);
+        } else if (value instanceof Boolean || "true".equals(value) || "false".equals(value)) {
+            return new ScalarNode(Tag.BOOL, String.valueOf(value), ScalarStyle.PLAIN);
+        } else if (value instanceof Map<?, ?> map) {
+            // Recursively handle nested maps
+            List<NodeTuple> mapTuples = new ArrayList<>();
+            for (Map.Entry<?, ?> entry : map.entrySet()) {
+                ScalarNode mapKeyNode =
+                        new ScalarNode(Tag.STR, String.valueOf(entry.getKey()), ScalarStyle.PLAIN);
+                Node mapValueNode = convertValueToNode(entry.getValue());
+                mapTuples.add(new NodeTuple(mapKeyNode, mapValueNode));
+            }
+            return new MappingNode(Tag.MAP, mapTuples, FlowStyle.BLOCK);
+        } else if (value instanceof List<?> list) {
+            List<Node> sequenceNodes = new ArrayList<>();
+            for (Object item : list) {
+                sequenceNodes.add(convertValueToNode(item));
+            }
+            return new SequenceNode(Tag.SEQ, sequenceNodes, FlowStyle.FLOW);
+        } else {
+            return new ScalarNode(Tag.STR, String.valueOf(value), ScalarStyle.PLAIN);
+        }
+    }
+
     /**
      * Copies comments from an old node to a new one.
      *

app/common/src/main/java/stirling/software/common/util/misc/ColorSpaceConversionStrategy.java

@@ -0,0 +1,86 @@
+package stirling.software.common.util.misc;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.core.io.InputStreamResource;
+import org.springframework.web.multipart.MultipartFile;
+
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.common.model.api.misc.ReplaceAndInvert;
+import stirling.software.common.util.ProcessExecutor;
+import stirling.software.common.util.ProcessExecutor.ProcessExecutorResult;
+import stirling.software.common.util.TempFile;
+import stirling.software.common.util.TempFileManager;
+
+@Slf4j
+public class ColorSpaceConversionStrategy extends ReplaceAndInvertColorStrategy {
+
+    private final TempFileManager tempFileManager;
+
+    public ColorSpaceConversionStrategy(
+            MultipartFile file,
+            ReplaceAndInvert replaceAndInvert,
+            TempFileManager tempFileManager) {
+        super(file, replaceAndInvert);
+        this.tempFileManager = tempFileManager;
+    }
+
+    @Override
+    public InputStreamResource replace() throws IOException {
+        try (TempFile tempInput = new TempFile(tempFileManager, ".pdf");
+                TempFile tempOutput = new TempFile(tempFileManager, ".pdf")) {
+
+            Path tempInputFile = tempInput.getPath();
+            Path tempOutputFile = tempOutput.getPath();
+
+            Files.write(tempInputFile, getFileInput().getBytes());
+
+            log.info("Starting CMYK color space conversion");
+
+            List<String> command = new ArrayList<>();
+            command.add("gs");
+            command.add("-sDEVICE=pdfwrite");
+            command.add("-dCompatibilityLevel=1.5");
+            command.add("-dPDFSETTINGS=/prepress");
+            command.add("-dNOPAUSE");
+            command.add("-dQUIET");
+            command.add("-dBATCH");
+            command.add("-sProcessColorModel=DeviceCMYK");
+            command.add("-sColorConversionStrategy=CMYK");
+            command.add("-sColorConversionStrategyForImages=CMYK");
+            command.add("-sOutputFile=" + tempOutputFile.toString());
+            command.add(tempInputFile.toString());
+
+            log.debug("Executing Ghostscript command for CMYK conversion: {}", command);
+
+            ProcessExecutorResult result =
+                    ProcessExecutor.getInstance(ProcessExecutor.Processes.GHOSTSCRIPT)
+                            .runCommandWithOutputHandling(command);
+
+            if (result.getRc() != 0) {
+                log.error(
+                        "Ghostscript CMYK conversion failed with return code: {}. Output: {}",
+                        result.getRc(),
+                        result.getMessages());
+                throw new IOException(
+                        "CMYK color space conversion failed: " + result.getMessages());
+            }
+
+            log.info("CMYK color space conversion completed successfully");
+
+            byte[] pdfBytes = Files.readAllBytes(tempOutputFile);
+            return new InputStreamResource(new ByteArrayInputStream(pdfBytes));
+
+        } catch (Exception e) {
+            log.warn("CMYK color space conversion failed", e);
+            throw new IOException(
+                    "Failed to convert PDF to CMYK color space: " + e.getMessage(), e);
+        }
+    }
+}

app/common/src/main/java/stirling/software/common/util/misc/InvertFullColorStrategy.java

@@ -19,7 +19,10 @@ import org.apache.pdfbox.rendering.PDFRenderer;
 import org.springframework.core.io.InputStreamResource;
 import org.springframework.web.multipart.MultipartFile;
 
+import stirling.software.common.model.ApplicationProperties;
 import stirling.software.common.model.api.misc.ReplaceAndInvert;
+import stirling.software.common.util.ApplicationContextProvider;
+import stirling.software.common.util.ExceptionUtils;
 
 public class InvertFullColorStrategy extends ReplaceAndInvertColorStrategy {
 
@@ -44,8 +47,25 @@ public class InvertFullColorStrategy extends ReplaceAndInvertColorStrategy {
             // Render each page and invert colors
             PDFRenderer pdfRenderer = new PDFRenderer(document);
             for (int page = 0; page < document.getNumberOfPages(); page++) {
-                BufferedImage image =
-                        pdfRenderer.renderImageWithDPI(page, 300); // Render page at 300 DPI
+                BufferedImage image;
+
+                // Use global maximum DPI setting, fallback to 300 if not set
+                int renderDpi = 300; // Default fallback
+                ApplicationProperties properties =
+                        ApplicationContextProvider.getBean(ApplicationProperties.class);
+                if (properties != null && properties.getSystem() != null) {
+                    renderDpi = properties.getSystem().getMaxDPI();
+                }
+
+                try {
+                    image =
+                            pdfRenderer.renderImageWithDPI(
+                                    page, renderDpi); // Render page with global DPI setting
+                } catch (OutOfMemoryError e) {
+                    throw ExceptionUtils.createOutOfMemoryDpiException(page + 1, renderDpi, e);
+                } catch (NegativeArraySizeException e) {
+                    throw ExceptionUtils.createOutOfMemoryDpiException(page + 1, renderDpi, e);
+                }
 
                 // Invert the colors
                 invertImageColors(image);