I am writing a desktop application in java which is for format conversion of all basic type of files. For e.g. word to pdf, pdf to word, png to jpeg, mp3 to wav etc. But there is no framework in java which is capable of doing these tasks. There exists some APIs for doing these tasks but many of them are not free or some are for web based applications. But I need an API which is written purely in java and is available freely and also can be used in desktop applications. I need an API in which i have to create the object of a class provided in API and then call methods of that class. So if you know about any API which is suitable for me, please help me.