org.junit.Test

The Test annotation tells JUnit that the public void method to which it is attached can be run as a test case. To run the method, JUnit first constructs a fresh instance of the class then invokes the annotated method. Any exceptions thrown by the test will be reported by JUnit as a failure. If no exceptions are thrown, the test is assumed to have succeeded.

A simple test looks like this:

public class Example {
   @Test 
   public void method() {
      org.junit.Assert.assertTrue( new ArrayList().isEmpty() );
   }
}

The Test annotation supports two optional parameters. The first, expected, declares that a test method should throw an exception. If it doesn't throw an exception or if it throws a different exception than the one declared, the test fails. For example, the following test succeeds:

   @Test(expected=IndexOutOfBoundsException.class) public void outOfBounds() {
      new ArrayList<Object>().get(1);
   }

The second optional parameter, timeout, causes a test to fail if it takes longer than a specified amount of clock time (measured in milliseconds). The following test fails:

   @Test(timeout=100) public void infinity() {
      while(true);
   }

 Class<Throwable> expected() 
{

}

 long timeout() 
{

}