Editing PDF text using Java

Question

Is there a way I can edit a PDF from Java?
I have a PDF document which contains placeholders for text that I need to be replaced using Java, but all the libraries that I saw created PDF from scratch and small editing functionality.
Is there anyway I can edit a PDF or is this impossible?

Answer 1

You can do it with iText. I tested it with following code. It adds a chunk of text and a red circle over each page of an existing PDF.

/* requires itextpdf-5.1.2.jar or similar */ import java.io.*; import com.itextpdf.text.DocumentException; import com.itextpdf.text.pdf.*;  public class AddContentToPDF {      public static void main(String[] args) throws IOException, DocumentException {          /* example inspired from "iText in action" (2006), chapter 2 */          PdfReader reader = new PdfReader("C:/temp/Bubi.pdf"); // input PDF         PdfStamper stamper = new PdfStamper(reader,           new FileOutputStream("C:/temp/Bubi_modified.pdf")); // output PDF         BaseFont bf = BaseFont.createFont(                 BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED); // set font          //loop on pages (1-based)         for (int i=1; i<=reader.getNumberOfPages(); i++){              // get object for writing over the existing content;             // you can also use getUnderContent for writing in the bottom layer             PdfContentByte over = stamper.getOverContent(i);              // write text             over.beginText();             over.setFontAndSize(bf, 10);    // set font and size             over.setTextMatrix(107, 740);   // set x,y position (0,0 is at the bottom left)             over.showText("I can write at page " + i);  // set text             over.endText();              // draw a red circle             over.setRGBColorStroke(0xFF, 0x00, 0x00);             over.setLineWidth(5f);             over.ellipse(250, 450, 350, 550);             over.stroke();         }          stamper.close();      } }