jPDFAssemble is a Java library to assemble PDF files. It can combine, merge, or split PDF documents, and allows the addition or manipulation of bookmarks. It can save resulting documents to the local filesystem or to an output stream, to be able to serve the documents directly to a client browser when working within a J2EE server. jPDFAssemble is built on top of Qoppa's proprietary PDF technology, so you do not have to install any third party software or drivers. It is also 100% Java, so it is completely platform-independent.

URL: jPDFAssemble | Java PDF Assemble Library to Merge and Split PDF documents