I am searching API for writing word document.
The way iText provides extensive functionality for writing into PDF, same i need for writing into word.
But I am unable to find.
I hv gone throgh Apache POI site, but i dont think it will serve my purpose.
My requirement -> writing text, images, tables, image sizing, header/footer, font styling etc..
The MS Word format is not as open as the PDF format. That makes it hard for people to write APIs for reading / manipulating it. Most libraries, like POI, have been created using reverse engineering of existing Word documents.
You could try using OpenOffice.org in server mode. I haven't done anything like that myself so I can't help you with it though. JODConverter uses this technique for converting from and to Word documents.
From my experience with POI it's unlikely that you will be able to create complex Word document with it - the DOC(X) part of it is way behind the XSL(X) part.
RTF is a much easier format to generate, though, is much better documented, and support everything you mention. Plus, every word processor can open it. Maybe that would be an alternative? iText 2.1 supports RTF as an output format.