JUnit rule for expected exception

gistfile1.java

public class TripServiceTest {
         
    private static final User UNUSED_USER = null;
    private static final User NON_LOGGED_USER = null;
    private User loggedUser = new User();
    private User targetUser = new User();
    private TripService tripService;
    @Rule
    public ExpectedException exception = ExpectedException.none();
 
    @Before
    public void initialise() {
        tripService  = createTripService();
    } 
         
    @Test public void
    shouldThrowExceptionWhenUserIsNotLoggedIn() throws Exception {
        loggedUser = NON_LOGGED_USER;
        exception.expect(UserNotLoggedInException.class);          
        tripService.getTripsByUser(UNUSED_USER);
    }
         
    @Test public void
    shouldNotReturnTripsWhenLoggedUserIsNotAFriend() throws Exception {             
        List<Trip> trips = tripService.getTripsByUser(targetUser);
                  
        assertThat(trips.size(), is(equalTo(0)));
    }
         
    @Test public void
    shouldReturnTripsWhenLoggedUserIsAFriend() throws Exception {
        User john = anUser().friendsWith(loggedUser)
                            .withTrips(new Trip(), new Trip())
                            .build();
                  
        List<Trip> trips = tripService.getTripsByUser(john);
                  
        assertThat(trips, is(equalTo(john.trips())));
    }
 
    private TripService createTripService() {
        return new TripService() {
            @Override protected User loggedUser() {
                return loggedUser;
            }
            @Override protected List<Trip> findTripsByUser(User user) {
                return user.trips();
            }
        };
    }        
}