Java Debugging: How to find difference in Code Flow Paths?

Question

Sometimes, while debugging Java Code I find myself doing the following to find bugs:

1. Put a breakpoint on a method invocation
2. Run the program in debug mode
3. Note the code flow path as a result of method invocation
4. Change the parameters and rerun the program in debug mode
5. Again note the code flow path from the point where the method is invoked
6. Find the difference between the code flow paths and zero in on the potential buggy path.

Is there a tool that makes this job easier by recording the code flow path in a file and comparing two such files?

Answer 1

Try using something like emma, it is a unit test code coverage tool which should be able to tell you which classes have unused or untested code paths.

There is a plugin available for eclipse that should provide a pretty concise report.

Answer 2

You can use logging. If you code path traversers libraries with source code out of your control you can set a conditional breakpoint that prints some message and returns false.