[antlr-interest] Get class name in *.java use antlr-2.7.6

[bou, hou (GE Money, consultant)]

hello all:
Who can give me a sample to get all class names in java source file with using antlr.And can I get the type of class , which as main class , class or inner class.
<http://www.antlr.org/doc/getting-started.html>
I have read the doc , but don't really understand.
May be you had used antlr, help me. 
thank u.