Hi Navdeep,
As you stated that you want to convert a VB application in Java and you have 2 choices.
If you want to convert the VB application into a Java Web Application then
you should go for JSF (Java Server Faces).
And if you want to convert the VB application into a Java Stand Alone Application then you should go for Swing. Although Swing have different libraries which are available for VB, you can look for rich third party libraries. SOme of them are free.
I hope you got my view.