Add an outline to a PDF

A PDF Outline (also known as bookmarks) allows users to navigate through the document, similarly to a contents page.

Adding an outline can be done programmatically. Copying an outline can be done programmatically or from the command line.

How to write an outline to a PDF file

Outlines are represented by a Document object.

final Document outline;
final OutlineWriter outlineWriter = new OutlineWriter("inputFile.pdf", outline);

try {
    outlineWriter.writeOutline();
} catch (final IOException | PdfException e) {
    e.printStackTrace();
}

How to copy an outline from one PDF file to another programmatically

JPedal also allows you to extract an outline from a PDF file meaning you can write it to another one.

More information here.

How to copy an outline from one PDF file to another using the command line

JPedal has a convenient way to copy an outline between PDF files using the command line.

java -jar jpedal.jar --copyoutline "inputFile.pdf" "outputFile.pdf"