Split PDFs in Java

To split a document, you can use the Document Editor. This example shows splitting a document into two files: “A.pdf” and “B.pdf”.

1. Create a DocumentEditor object from the original document:

   final PdfDocument document = PdfDocument.open(new FileDataProvider(new File("documentToSplit.pdf")));
   final DocumentEditor documentEditor = document.createDocumentEditor();

2. Identify which pages should be in document “A” and use removePages to remove the pages that remain:

   // Identify the pages that need to be split.
   final int[] pagesToSplit = new int[] {3, 4, 5};
   documentEditor.RemovePages(pagesToSplit);

3. Save document “A” to a new location:

   // Save the document to an output file.
   final String filename = "A.pdf";
   documentEditor.saveDocument(new FileDataProvider(new File(filename)));

4. Using a function such as the one below will make this process simpler:

   void exportSectionOfDocument(String originalDocument, String outputDocument, int[] pagesToExport)
   {
       final PdfDocument document = PdfDocument.open(new FileDataProvider(new File(originalDocument)));
       final DocumentEditor documentEditor = document.createDocumentEditor();
   
       // Search the document for pages that should not be exported and add them to
       // a `pagesToRemove` set.
       final Set<Integer> pagesToRemove = new HashSet<>();
       for (int i = 0; i < document.getPageCount(); i++) {
           if (Arrays.binarySearch(pagesToExport, i) < 0) {
               pagesToRemove.add(i);
           }
       }
       documentEditor.removePages(pagesToRemove);
   
       // Save the new document to the specified output location.
       documentEditor.saveDocument(new FileDataProvider(new File(outputDocument)));
   }

5. Repeat the steps for document “B”:

   exportSectionOfDocument("documentToSplit.pdf", "B.pdf", new int[] {0, 1, 2});