The JUnit framework is arguably the de-facto standard for unit testing java code, and is also the basis of many other testing frameworks (unit or otherwise). Using the JUnit framework, one can quickly run a test method, class, or suite and get one of three responses: Success: All of the assertions in the test method passed, no fail calls were encountered, and no unexpected exceptions were thrown. Failure: One of the assertions in the test method failed or a fail call was encountered. Error: An unexpected java.lang.Throwable was thrown within the test method's body.