How to access Desktop applicaiton from web application

How can we access desktop api/methods from web application(java based)? An example what I mean by this is: I have developed simple java based desktop application which has database(data stored in Xml format), I want to call desktop api in web application. How can I access desktop application methods/api from web application or basically how to write web wrapper for desktop application to access api in web application? Some sample codes would be good...

Thank you in advance