JUnit provides both a graphical and a textual version of a TestRunner tool. Start it by typing java junit.ui.TestRunner or junit.swingui.TestRunner . In the case of an unsuccessful test JUnit reports the failed tests in a list at the bottom. JUnit distinguishes between failures and errors . A failure is anticipated and checked for with assertions.
Errors are unanticipated problems like an ArrayIndexOutOfBoundsException .
The following figure shows an example of a failed test. To find out more about a failure or an error select it in the list and press Show. This will show you a stack trace of the failure. In a dynamic programming environment like VisualAge for Java which supports hot code update you can leave the JUnit window up all the time. In other environments you have to restart the graphical version for each run.