How to merge two PDF files into one in Java?

Question

I want to merge many PDF files into one using PDFBox and this is what I've done:

PDDocument document = new PDDocument(); for (String pdfFile: pdfFiles) {     PDDocument part = PDDocument.load(pdfFile);     List<PDPage> list = part.getDocumentCatalog().getAllPages();     for (PDPage page: list) {         document.addPage(page);     }     part.close(); } document.save("merged.pdf"); document.close(); 

Where pdfFiles is an ArrayList<String> containing all the PDF files.

When I'm running the above, I'm always getting:

org.apache.pdfbox.exceptions.COSVisitorException: Bad file descriptor 

Am I doing something wrong? Is there any other way of doing it?

Answer 1

Why not use the PDFMergerUtility of pdfbox?

PDFMergerUtility ut = new PDFMergerUtility(); ut.addSource(...); ut.addSource(...); ut.addSource(...); ut.setDestinationFileName(...); ut.mergeDocuments();