Summary: I've been working extensively on automating text replacement in PDF documents using Java. My goal is to preserve the original formatting and structure of the PDFs. Despite trying multiple approaches, I haven't been able to achieve the desired results. I'm seeking advice on what I might be missing in my implementation.
Approaches I have Tried Approach 1: Using PDFBox to Extract, Edit, and Reinsert Text
package PDFbox;
import .apache.pdfbox.pdmodel.PDDocument;
import .apache.pdfbox.text.PDFTextStripper;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
public class ExtractText {
public static void main(String[] args) throws IOException {
if (args.length < 2) {
System.err.println("Usage: java ExtractText <pdfFilePath> <outputTextFilePath>");
return;
}
String pdfFilePath = args[0];
String outputTextFilePath = args[1];
try (PDDocument document = PDDocument.load(new File(pdfFilePath));
FileWriter writer = new FileWriter(outputTextFilePath)) {
PDFTextStripper textStripper = new PDFTextStripper();
String text = textStripper.getText(document);
writer.write(text);
System.out.println("Text content extracted and saved to " + outputTextFilePath);
}
}
}
Edited the Text:
Manually edited the extracted text in a text file.
package PDFbox;
import .apache.pdfbox.pdmodel.PDDocument;
import .apache.pdfbox.pdmodel.PDPage;
import .apache.pdfbox.pdmodel.PDPageContentStream;
import .apache.pdfbox.pdmodel.font.PDType1Font;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
public class InsertText {
public static void main(String[] args) throws IOException {
if (args.length < 3) {
System.err.println("Usage: java InsertText <pdfFilePath> <textFilePath> <outputPdfFilePath>");
return;
}
String pdfFilePath = args[0];
String textFilePath = args[1];
String outputPdfFilePath = args[2];
// Load the text content
String editedText = new String(Files.readAllBytes(Paths.get(textFilePath)));
try (PDDocument document = PDDocument.load(new File(pdfFilePath))) {
PDPage page = document.getPage(0);
// Modify the page content
try (PDPageContentStream contentStream = new PDPageContentStream(document, page, PDPageContentStream.AppendMode.APPEND, true, true)) {
contentStream.beginText();
contentStream.setFont(PDType1Font.HELVETICA, 12);
contentStream.newLineAtOffset(25, 750);
// Split text into lines to handle line breaks
String[] lines = editedText.split("\n");
for (String line : lines) {
contentStream.showText(line);
contentStream.newLineAtOffset(0, -15); // Move to the next line
}
contentStream.endText();
}
// Save the updated PDF
document.save(outputPdfFilePath);
System.out.println("Edited text inserted and PDF saved to " + outputPdfFilePath);
}
}
}
Attempted to Re-insert the Text:
package PDFbox;
import .apache.pdfbox.pdmodel.PDDocument;
import .apache.pdfbox.pdmodel.PDPage;
import .apache.pdfbox.pdmodel.PDPageContentStream;
import .apache.pdfbox.pdmodel.font.PDType1Font;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
public class InsertText {
public static void main(String[] args) throws IOException {
if (args.length < 3) {
System.err.println("Usage: java InsertText <pdfFilePath> <textFilePath> <outputPdfFilePath>");
return;
}
String pdfFilePath = args[0];
String textFilePath = args[1];
String outputPdfFilePath = args[2];
// Load the text content
String editedText = new String(Files.readAllBytes(Paths.get(textFilePath)));
try (PDDocument document = PDDocument.load(new File(pdfFilePath))) {
PDPage page = document.getPage(0);
// Modify the page content
try (PDPageContentStream contentStream = new PDPageContentStream(document, page, PDPageContentStream.AppendMode.APPEND, true, true)) {
contentStream.beginText();
contentStream.setFont(PDType1Font.HELVETICA, 12);
contentStream.newLineAtOffset(25, 750);
// Split text into lines to handle line breaks
String[] lines = editedText.split("\n");
for (String line : lines) {
contentStream.showText(line);
contentStream.newLineAtOffset(0, -15); // Move to the next line
}
contentStream.endText();
}
// Save the updated PDF
document.save(outputPdfFilePath);
System.out.println("Edited text inserted and PDF saved to " + outputPdfFilePath);
}
}
}
Challenges:
- The formatting and layout of the PDF are significantly altered after editing.
- Issues with text alignment, fonts, and page breaks.
Approach 2: Using iText to Extract, Edit, and Reinsert Text
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.parser.PdfTextExtractor;
public class ExtractTextUsingIText {
public static void main(String[] args) {
try {
PdfReader reader = new PdfReader("path/to/pdf");
String text = PdfTextExtractor.getTextFromPage(reader, 1);
System.out.println(text);
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
Edited the Text:
Manually edited the extracted text in a text file.
Attempted to Re-insert the Text:
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.pdf.PdfWriter;
import java.io.FileOutputStream;
import java.io.IOException;
public class InsertTextUsingIText {
public static void main(String[] args) {
Document document = new Document();
try {
PdfWriter.getInstance(document, new FileOutputStream("path/to/edited_pdf"));
document.open();
document.add(new Paragraph("Edited text goes here"));
document.close();
System.out.println("Edited text inserted and PDF saved");
} catch (DocumentException | IOException e) {
e.printStackTrace();
}
}
}
Challenges:
- The PDF structure is disrupted after editing.
- Loss of original formatting and layout.
Approach 3: Editing Binary Data
Exported PDF Content to Binary:
package PDFbox;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class ExportPDFAsBinary {
public static void main(String[] args) throws IOException {
if (args.length < 2) {
System.err.println("Usage: java ExportPDFAsBinary <sourcePdfPath> <outputBinaryFilePath>");
return;
}
String sourcePdfPath = args[0];
String outputBinaryFilePath = args[1];
try (FileInputStream fis = new FileInputStream(new File(sourcePdfPath));
FileOutputStream fos = new FileOutputStream(new File(outputBinaryFilePath))) {
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = fis.read(buffer)) != -1) {
fos.write(buffer, 0, bytesRead);
}
System.out.println("PDF content exported as binary data to " + outputBinaryFilePath);
}
}
}
Edited Binary Data:
package PDFbox;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
public class EditBinaryPDF {
public static void main(String[] args) throws IOException {
if (args.length < 4) {
System.err.println("Usage: java EditBinaryPDF <binaryFilePath> <outputBinaryFilePath> <searchString> <replaceString>");
return;
}
String binaryFilePath = args[0];
String outputBinaryFilePath = args[1];
String searchString = args[2];
String replaceString = args[3];
// Ensure search and replace strings are of the same length
if (searchString.length() != replaceString.length()) {
System.err.println("Search and replace strings must be of the same length");
return;
}
// Read the binary file into a byte array
byte[] binaryData = readBinaryFile(binaryFilePath);
// Convert search and replace strings to byte arrays
byte[] searchBytes = searchString.getBytes(StandardCharsets.ISO_8859_1);
byte[] replaceBytes = replaceString.getBytes(StandardCharsets.ISO_8859_1);
// Edit the binary data
binaryData = replaceTextInBinaryData(binaryData, searchBytes, replaceBytes);
// Save the edited binary data to the output file
try (FileOutputStream fos = new FileOutputStream(new File(outputBinaryFilePath))) {
fos.write(binaryData);
}
System.out.println("Edited binary data saved to " + outputBinaryFilePath);
}
private static byte[] readBinaryFile(String filePath) throws IOException {
File file = new File(filePath);
byte[] binaryData = new byte[(int) file.length()];
try (FileInputStream fis = new FileInputStream(file)) {
fis.read(binaryData);
}
return binaryData;
}
private static byte[] replaceTextInBinaryData(byte[] binaryData, byte[] searchBytes, byte[] replaceBytes) {
for (int i = 0; i <= binaryData.length - searchBytes.length; i++) {
boolean match = true;
for (int j = 0; j < searchBytes.length; j++) {
if (binaryData[i + j] != searchBytes[j]) {
match = false;
break;
}
}
if (match) {
System.arraycopy(replaceBytes, 0, binaryData, i, replaceBytes.length);
i += searchBytes.length - 1; // Move past the replaced text
}
ReCreated PDF out of .binary file
package PDFbox;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class RecreatePDFFromBinary {
public static void main(String[] args) throws IOException {
if (args.length < 2) {
System.err.println("Usage: java RecreatePDFFromBinary <inputBinaryFilePath> <outputPdfPath>");
return;
}
String inputBinaryFilePath = args[0];
String outputPdfPath = args[1];
try (FileInputStream fis = new FileInputStream(new File(inputBinaryFilePath));
FileOutputStream fos = new FileOutputStream(new File(outputPdfPath))) {
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = fis.read(buffer)) != -1) {
fos.write(buffer, 0, bytesRead);
}
System.out.println("PDF recreated from binary data at " + outputPdfPath);
}
}
}
ExportPDFAsBinary: output file should be a .binary extension and it worked 100% fine
RecreatePDFFromBinary also worked absolutely fine but if the binary file was edited then output PDF file was totally messed up
Any help or breakthrough will be highly appreciated. Note: I also tried JavaScript feature inside Adobe Acrobat Pro but that also did not work. Reading through the documentation I came to conclusion that Adobe discourages automation.