Right now I have both type of tests but when I say "mvn test" it only executes TestNG tests and not Junit. I want to execute both one after another. Any Idea ?
There is an open issue for this, so there's no elegant way to do this.
It would be far simpler for you to pick a framework and stick with it.
Edit: My previous answer doesn't work because you can't specify dependencies in the execution. I've tried a few approaches, but the best I can manage is to create a profile for the TestNG dependency so you can toggle between TestNG and JUnit testing, there doesn't seem to be a means to run both TestNG and Junit 4 tests.
One other point to note: You can launch your JUnit tests from TestNG, but I think this only works for JUnit 3 tests.