This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
I recommend you don't try to do this yourself and use a java library that exists already for this. I've used the one from the site http://www.json.org/ and it would be more than useable in your situation.