When to use what Testing tools?

1.) Unit test cases : All the unit test cases of the code should pass, you can use JUnit. TestNG
2.) Various code quality standards should satisfy a benchmark i.e
         a.) For code coverage you can use cobertura
         b.) Static code analysis : their are couple of tools findbug, checkstyle, pmd.
              You can use Sonar as well which consolidates a lot of things.
3.) API test : Fitness can be used for doing API testing
4.) Functional/Integration testing : Selenium/QTP/ can be used for it
5.) Performance testing : JMeter/load runner can be used for this