GetPages error while migrating PDFBox to 2.x

Question

Im migrating my PDFBox 1.8.x to 2.0.12 and have to fight some changes.

The last one that I can't figure out is occuring in the code seen below.

    public static byte[] mergeDocuments(byte[] document1, byte[] document2) {
    try (PDDocument pdDocument1 = load(document1); PDDocument pdDocument2 = load(document2)) {
        final List<PDPage> pages1 = getPages(pdDocument1);
        final List<PDPage> pages2 = getPages(pdDocument2);
        pages1.addAll(pages2);
        return createDocument(pages1);
    } catch (IOException e) {
        throw new RuntimeException(e);
    }
}

private static List getPages(PDDocument pdDocumentTarget) {
    return pdDocumentTarget.getDocumentCatalog().getAllPages();
}

Error occurs on the last line, I have to change the old ".getAllPages()" to ".getPages", but then I get PDPageTree as return and not List.

Code is written some years ago and not by me. I have tried some things like casting or changing the types, but it allways results in errors in different places.

Thanks in advance for any help

Additional to the answer, you can also try `document.getPage(i)` together with `document.getNumberOfPages()` — Tilman Hausherr, Oct 10 '18 at 17:50

score 2 · Accepted Answer · answered Oct 10 '18 at 14:14

PDPageTree implements Iterable<PDPage>, so you effectively need a way to generate a List for an Iterable.

This question illustrates many ways to do so, e.g. assuming Java 8:

private static List<PDPage> getPages(PDDocument pdDocumentTarget) {
    List<PDPage> result = new ArrayList<>();
    pdDocumentTarget.getPages().forEach(result::add);
    return result;
}

GetPages error while migrating PDFBox to 2.x

1 Answers1