The Apache PDFBox library is an open source Java tool for working with PDF
documents. This project allows creation of new PDF documents, manipulation of
existing documents and the ability to extract content from documents. Apache
PDFBox also includes several command line utilities.

Features:
 - Text extraction
 - Merging & Splitting
 - Forms Filling
 - PDF/A Validation
 - PDF Printing
 - PDF to Image Conversion
 - PDF Creation
 - PDF Signing

WWW: http://pdfbox.apache.org/