Maybe the most disturbing thing about Docear is the lack of a proper PDF reader that creates comments, bookmarks and highlighted text that can be imported by Docear and that runs on all operating systems. Personally, I use Foxit Reader and create bookmarks to remember important statements but it can’t highlight text properly. PDF XChange Viewer could be a great alternative if they had persistent object numbers – but they don’t (read here for more details).
Due to the lack of a truly proper Java PDF viewer, we are considering to develop our own PDF viewer. There are plenty of Java PDF libraries out there. However, I had a look at them and none of seem is really suitable. Aspose PDF, iText, jPod Renderer>, PDF Tron, Big Faceless Java PDF, CABAReT Stage, jPDFBookmarks, JPedal, PDFBox, ICE Pdf, ReMarksPDF, and Qoppa’s jPDFViewer all have some shortcomings. Either they have many features but are commercial (e.g. Big Faceless Java PDF), or they are open source but do not offer the required feature or have serious bugs (e.g. PDFBox).
So, my question: Do you know of any other Java PDF libraries or even better a fully functional Java PDF viewer? Our requirements are: