How to convert the Dynamic xfa form to XML data in Java?

I got mail for xfa dynamic form and like to write simple jave to convert the xfa form data into xml file or at least how do I get the input date from the dynamic xfa form using Java?
 
In Adobe Reader X:
View > Extended > Extened Features > Export Data (under the Forms)
to export the XML data file.
Now how do I write Java code to get the xfa input data from the dynamic xfa form?
   
Thanks