From Qoppa Software:
jPDFAssemble for Linux is a Java library to assemble PDF files. It also allows to add or manipulate bookmarks in PDF documents. The library can save resulting documents to the local file system or to an output stream to be able to serve the documents directly to a client browser when working within a J2EE server. It create new bookmarks or edit existing bookmarks or outlines, save to the file system or to Java output streams and written entirely in Java so it allows your application to remain platform independent. No need to install or configure additional drivers or software when deploying your application.