PDF Helper

The PDFHelper class provides utilities for working with PDF files. It offers functionality for reading, writing, merging, splitting, encrypting, and manipulating PDF documents using the Apache PDFBox library.

Basic PDF Operations

Reading PDF Files

// Extract text from a PDF file
String content = PDFHelper.readPdf("documents/report.pdf");

Writing PDF Files

// Write content to a new PDF file
List<String> lines = Arrays.asList(
    "Line 1: This is the first line of text.",
    "Line 2: This is the second line of text.",
    "Line 3: This is the third line of text."
);
PDFHelper.writePdf("documents/output.pdf", lines);

// Append content to an existing PDF file
List<String> additionalLines = Arrays.asList(
    "Additional line 1",
    "Additional line 2"
);
PDFHelper.appendToPdf("documents/report.pdf", additionalLines);

Page Management

// Get the total number of pages in a PDF
int pageCount = PDFHelper.getPageCount("documents/document.pdf");

// Extract a single page from a PDF file
PDFHelper.extractPdfPage(
    "documents/report.pdf", 
    "documents/extracted_page.pdf", 
    2 // page index (zero-based)
);

// Remove pages from a PDF
PDFHelper.removePages(
    "documents/report.pdf", 
    "documents/shortened.pdf", 
    5, // start page (inclusive, zero-based)
    10 // end page (inclusive, zero-based)
);

// Rotate a specific page
PDFHelper.rotatePage(
    "documents/document.pdf", 
    "documents/rotated.pdf", 
    0, // page index 
    90 // rotation degrees (90, 180, 270)
);

// Add blank pages to a PDF
PDFHelper.addBlankPages(
    "documents/document.pdf", 
    3 // number of blank pages to add
);

// Get dimensions of a specific page
PDRectangle dimensions = PDFHelper.getPageDimensions(
    "documents/document.pdf",
    0 // page index
);
float width = dimensions.getWidth();
float height = dimensions.getHeight();

PDF Manipulation

Merging and Splitting

// Merge multiple PDF files into one
List<String> filesToMerge = Arrays.asList(
    "documents/part1.pdf",
    "documents/part2.pdf",
    "documents/part3.pdf"
);
PDFHelper.mergePdfs(filesToMerge, "documents/merged.pdf");

// Split a PDF into individual pages
PDFHelper.splitPdf(
    "documents/document.pdf", 
    "documents/split/" // output directory
);

Adding Content

// Add an image to a PDF
PDFHelper.addImageToPdf(
    "documents/document.pdf", 
    "documents/with_image.pdf", 
    "images/logo.png", 
    100, // x position
    100, // y position
    200, // width
    100  // height
);

// Add a watermark to a PDF
PDFHelper.addWatermark(
    "documents/document.pdf", 
    "documents/watermarked.pdf", 
    "CONFIDENTIAL"
);

PDF Security

// Encrypt a PDF with password protection
PDFHelper.encryptPdf(
    "documents/document.pdf", 
    "documents/encrypted.pdf", 
    "owner-password", 
    "user-password"
);

// Check if a PDF is encrypted
boolean isEncrypted = PDFHelper.isEncrypted(
    "documents/document.pdf", 
    "password" // optional password to try
);

PDF Optimization

// Compress a PDF to reduce file size
PDFHelper.compressPDF(
    "documents/large.pdf", 
    "documents/compressed.pdf"
);

// Flatten form fields in a PDF
PDFHelper.flattenFormFields(
    "documents/form.pdf", 
    "documents/flattened.pdf"
);

Metadata Management

// Update PDF metadata
PDFHelper.updateMetadata(
    "documents/document.pdf", 
    "documents/updated.pdf", 
    "Report Title", // title
    "John Doe"      // author
);

PDF Comparison

// Compare two PDF files for content equality
boolean areEqual = PDFHelper.comparePdfFiles(
    "documents/original.pdf", 
    "documents/copy.pdf"
);

Error Handling

The PDFHelper class incorporates robust error handling and logging through the Ellithium reporting system. All operations log their status, making it easy to trace PDF operations during test execution.

// All methods include proper error handling and logging
try {
    String content = PDFHelper.readPdf("nonexistent.pdf");
    // Logs: "File does not exist: nonexistent.pdf"
} catch (Exception e) {
    // Additional error handling if needed
}

Performance Considerations

Working with PDFs can be memory-intensive, especially for large files. The PDFHelper class is designed to efficiently manage resources by:

1. Using try-with-resources to ensure proper document closure
2. Providing targeted operations to work with specific pages rather than entire documents when possible
3. Offering compression options for reducing file sizes