JODConverter, the Java OpenDocument Converter, converts documents between different office formats.
It leverages OpenOffice.org, which provides arguably the best import/export filters for OpenDocument and Microsoft Office formats available today.

JODConverter can be used in many different ways

• As a Java library, embedded in your own Java application
• As a command line tool, possibly invoked from your own scripts
• As a simple web application: upload your input document, select the desired format and download the converted version
• As a web service, invoked from your own application written in your favourite language (.NET, PHP, Python, Ruby, …)

JODConverter is open source software released under the terms of the LGPL and can be downloaded from SourceForge.net.

http://www.artofsolving.com/opensource/jodconverter