How do you assert that a certain exception is thrown in JUnit 4 tests?

Question

How can I use JUnit4 idiomatically to test that some code throws an exception?

While I can certainly do something like this:

@Test
public void testFo         


        

Answer 1

We can use an assertion fail after the method that must return an exception:

try{
   methodThatThrowMyException();
   Assert.fail("MyException is not thrown !");
} catch (final Exception exception) {
   // Verify if the thrown exception is instance of MyException, otherwise throws an assert failure
   assertTrue(exception instanceof MyException, "An exception other than MyException is thrown !");
   // In case of verifying the error message
   MyException myException = (MyException) exception;
   assertEquals("EXPECTED ERROR MESSAGE", myException.getMessage());
}