junit testing question

[Scott Purcell]

I have got some textbook example of <junit> working with simple classes that implement 
TestCase. But my question is as follows:
 
Prior to using ant, our code base was written to use a TestSuite(xxx.class)
And we ran them via a script like so:
java junit.textui.TestRunner classname
 
Can I still use these with ant? or do I need to rewrite the tests?
 
Any help or links, would be helpful.
 
Sincerely
Scott