Write JUnit test for @ExceptionHandler

Question

I am writing a Rest service using Spring MVC. Here is the outline of the class:

 @Controller
 public class MyController{

     @RequestMapping(..)
     public vo         


        

Answer 1

Consider using Spring 3.2 and its mvc-test-framework

import static org.springframework.test.web.servlet.setup.MockMvcBuilders.*;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration("file:src/main/webapp/WEB-INF/spring/appServlet/servlet-context.xml")
public class WebMvcTest {

    @Autowired
    private WebApplicationContext wac;

    private MockMvc mockMvc;

    @Before
    public void setup() {
        this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();
    }

    @Test
    public void getFoo() throws Exception {
        this.mockMvc.perform(
            get("/testx")
            .contentType(MediaType.APPLICATION_JSON)
            .accept(MediaType.APPLICATION_JSON)
            )
            .andExpect(status().isUnauthorized());
    }
}

Controller code

@Controller
public class MyController {

    public class MyException extends RuntimeException {
    };

    @RequestMapping("/testx")
    public void myMethod() {
        throw new MyException();

    }

    @ExceptionHandler(MyException.class)
    @ResponseStatus(value = HttpStatus.UNAUTHORIZED, reason = "blah")
    public void handler() {
        System.out.println("handler processed");
    }
}

This "test" passes well.

_{Disclaimer: currently I'm a noob in Spring MVC testing, actually it's my first test.
upd: Thanks to The Drake for the correction.}

Answer 2

Annotate your Exception Handling controller with @ControllerAdvice instead of @Controller.

As Boris Treukhov noted when adding the @ExceptionHandler annotation to a method in the controller that throws the exception will make it work but only from that specific controller.

@ControllerAdvice will allow your exception handeling methods to be applicable for your whole application not just one specific controller.

Answer 3

You could change @Test to

@Test(expected=NotAuthorizedException.class)

This would return true if the internals throw up that exception and false otherwise.

This would also make the assertThat() unnecessary. You could write a second test that catches the NotAuthorizedException then you could inspect the responseMock under that condition then.