Eclipse won't compile/run java file

Question

I am just trying to compile and run a simple java program. When I go to run my tester class it says select what to run and it gives me Ant Build which when highlighted says

Answer 1

I was also in the same problem, check your build path in eclipse by Right Click on Project > build path > configure build path

Now check for Excluded Files, it should not have your file specified there by any means or by regex.

Cheers!