File extension getter

Question

Is there a method in the API that will get the file extension off of a file name so that I can filter out certain ones. I'm providing an example just in case I'm using the wrong terminology, which could be why I'm having trouble finding it in the API.
ex: MyProgram.java
and then I only want to print it to the screen if it has the java extension.

Answer 1

"Extension" isn't a cross-platform concept, so Java
hasn't gone out of its way to support it. Follow
walken16's suggestion of writing your own.
(It's trickier than you might think. Watch out for
edge cases like ".net" and "Finally." and
"too.many.dots".)Could you clarify what you mean by: '...........cases like ".net".................'
I had always assumed that an extension was an extension was an extension......
I only program on windows............
I normally use this in my code:
     Gets The Extension.
     @param     f     A File To get The Extension of
     @return     The Extension part of the FileName.
     public static String getExtension( File f )
          String fileName;
          int index;
          int L;
          if( f != null )
               fileName = f.getName();
               L = fileName.length();
               index = fileName.lastIndexOf('.');
               if( (index > 0) && (index < (L - 1)) )
                    return fileName.substring( index + 1 ).toLowerCase();
          return null;
     }and just assumed that if somone renamed a file as blah.exe.old they meant it, and that Windows only ever cares about the .old part.
Am I missing something?
Not that anyone would ever get to run my programs, being just a hobbyist, still I like to think I'm learning the right way...........