How to load Classes?

How to retrive the class name during runtime.....

suppose if i select java.lang package , i must get all the classes relating to lang package....

i used reflection API, but using that you can retrive constructor and methods of any class... and i need the classes of perticular package.... how to do it?

Thank You

[338 byte] By [MadhuCMa] at [2007-10-3 4:39:15]