Question

This is what I want to do:

1. Make 2 different pdf files using pdfbox

2. Merge these two files together using pdfmerger

I know how to do this if I’m saving #1 to the server side local hard drive and load the files for the #2. But what I want to do is using “directly from the memory”. I’ve searched all the methods from this pdfboxes but still couldn’t find it.

This is my code getting from the local file

Thank you.

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import org.apache.pdfbox.exceptions.COSVisitorException;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.edit.PDPageContentStream;
import org.apache.pdfbox.pdmodel.font.PDFont;
import org.apache.pdfbox.pdmodel.font.PDTrueTypeFont;
import org.apache.pdfbox.pdmodel.font.PDType1Font;
import org.apache.pdfbox.util.PDFMergerUtility;

/**
* This is an example that creates a simple document
* with a ttf-font.
*
* @author <a href="mailto:[e-mail]">Michael Niedermair</a>
* @version $Revision: 1.2 $
*/
public class Test2
{

    /**
    * create the second sample document from the PDF file format specification.
    *
    * @param file     The file to write the PDF to.
    * @param message    The message to write in the file.
    * @param fontfile  The ttf-font file.
    *
    * @throws IOException If there is an error writing the data.
    * @throws COSVisitorException If there is an error writing the PDF.
    */
    public void doIt(final String file, final String message) throws IOException, COSVisitorException
    {

        // the document
        PDDocument doc = null;
        try
        {
            doc = new PDDocument();

            PDPage page = new PDPage();
            doc.addPage(page);
            PDFont font = PDType1Font.HELVETICA_BOLD;


            PDPageContentStream contentStream = new PDPageContentStream(doc, page);
            contentStream.beginText();
            contentStream.setFont(font, 12);
            contentStream.moveTextPositionByAmount(100, 700);
            contentStream.drawString(message);
            contentStream.endText();
            contentStream.close();

            doc.save(file);

            System.out.println(file + " created!");
        }
        finally
        {
            if (doc != null)
            {
                doc.close();
            }
        }
    }

    /**
     * This will create a hello world PDF document
     * with a ttf-font.
     * <br />
     * see usage() for commandline
     *
     * @param args Command line arguments.
     */
    public static void main(String[] args)
    {

        Test2 app = new Test2();
        Test2 app2 = new Test2();
        try {
            app.doIt("C:/here.pdf", "hello");
            app2.doIt("C:/here2.pdf", "helloagain");
            PDFMergerUtility merger = new PDFMergerUtility();
            merger.addSource("C:/here.pdf");
            merger.addSource("C:/here2.pdf");
            OutputStream bout2 = new BufferedOutputStream(new FileOutputStream("C:/hereisthefinal.pdf"));

            merger.setDestinationStream(bout2);
            merger.mergeDocuments();

        } catch (COSVisitorException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

Answer 1

You just need to use the PdfMergeUtility.addSource(InputStream) method to add source from an inputstream and not from a physical file.

With a quick glance at the API, what you could do is use the PDDocument.save(OutputStream) method to write the file into a byte array in memory, something like this should work.

static byte[] doIt(String message) {
   PDDocument doc = new PDDocument();
   // add the message
   ByteArrayOutputStream baos = new ByteArrayOutputStream();
   doc.save(baos);
   return baos.toByteArray();
}

void main(String args[]) {
   byte[] pdf1 = doIt("hello");
   byte[] pdf2 = doIt("world");
   PDFMergerUtility merger = new PDFMergerUtility();
   merger.addSource(new ByteArrayInputStream(pdf1));
   merger.addSource(new ByteArrayInputStream(pdf2));
   // do the rest with the merger
}