This appendix showed you how to test the components of your application either on their own using unit tests or in cooperation with other components in integration tests. You can also be confident that most of your code is tested by using test coverage tools. In addition, you can prove that the code you have implemented runs fast enough and does not crash under extreme stress if it passes the performance tests.
You also know which tools to choose for your tests, whether it is JUnit for unit and integration testing, Cactus EJB for web testing, JMeter for web and performance testing, or Clover, jcoverage, or EMMA for test coverage.