How to unit test a Spring MVC annotated controller?

Question

I am following a Spring 2.5 tutorial and trying, at the same time, updating the code/setup to Spring 3.0.

In Spring 2.5 I had the HelloController (for reference):

public class HelloController implements Controller {
    protected final Log logger = LogFactory.getLog(getClass());
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        logger.info("Returning hello view");
        return new ModelAndView("hello.jsp");
    }
}

And a JUnit test for the HelloController (for reference):

public class HelloControllerTests extends TestCase {
    public void testHandleRequestView() throws Exception{
        HelloController controller = new HelloController();
        ModelAndView modelAndView = controller.handleRequest(null, null);
        assertEquals("hello", modelAndView.getViewName());
    }
}

But now I updated the controller to Spring 3.0, and it now uses annotations (I also added a message):

@Controller
public class HelloController {
    protected final Log logger = LogFactory.getLog(getClass());
    @RequestMapping("/hello")
    public ModelAndView handleRequest() {
        logger.info("Returning hello view");
        return new ModelAndView("hello", "message", "THIS IS A MESSAGE");
    }
}

Knowing that I am using JUnit 4.9, can some one explain me how to unit test this last controller?

possible duplicate of How to unit test a Spring MVC controller using @PathVariable? — Raedwald
– Raedwald, Commented Jan 23, 2014 at 8:30

nunaxe · Accepted Answer · 2011-04-25 12:09:16Z

25

One advantage of annotation-based Spring MVC is that they can be tested in a straightforward manner, like so:

import org.junit.Test;
import org.junit.Assert;
import org.springframework.web.servlet.ModelAndView;

public class HelloControllerTest {
   @Test
   public void testHelloController() {
       HelloController c= new HelloController();
       ModelAndView mav= c.handleRequest();
       Assert.assertEquals("hello", mav.getViewName());
       ...
   }
}

Is there any problem with this approach?

For more advanced integration testing, there is a reference in Spring documentation to the org.springframework.mock.web.

edited Apr 25, 2011 at 12:09

nunaxe

1,4202 gold badges15 silver badges16 bronze badges

answered Apr 25, 2011 at 1:57

Sasha O

3,7492 gold badges37 silver badges46 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

nunaxe Over a year ago

+1 Thank you so much Sasha. It works great. I couldn't imagine it was so simple.

Aram Kocharyan Over a year ago

This won't work if there are @Autowired components in HelloController

Sasha O Over a year ago

@AramKocharyan: in unit tests I would recommend against using Autowired and supply dependencies explicitly, via constructor or setters. If you really want all the Spring goodness you may want to look into static.springsource.org/spring/docs/3.0.x/…

Aram Kocharyan Over a year ago

@SashaO yeah learnt that this week :P I'm just setting the autowired instance with a setter as you say, worked well.

Rafael Over a year ago

I find this approach too white box. The fact that the view is called "hello" doesn't mean is doing what needs to do. We are unit testing our controllers using HttpClient. Just as if the test were the browser.

|

Dejan P · Accepted Answer · 2011-10-27 13:12:32Z

21

With mvc:annotation-driven you have to have 2 steps: first you resolve the request to handler using HandlerMapping, then you can execute the method using that handler via HandlerAdapter. Something like:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("yourContext.xml")
public class ControllerTest {

    @Autowired
    private RequestMappingHandlerAdapter handlerAdapter;

    @Autowired
    private RequestMappingHandlerMapping handlerMapping;

    @Test
    public void testController() throws Exception {
        MockHttpServletRequest request = new MockHttpServletRequest();
        // request init here

        MockHttpServletResponse response = new MockHttpServletResponse();
        Object handler = handlerMapping.getHandler(request).getHandler();
        ModelAndView modelAndView = handlerAdapter.handle(request, response, handler);

        // modelAndView and/or response asserts here
    }
}

This works with Spring 3.1, but I guess some variant of this must exist for every version. Looking at the Spring 3.0 code, I'd say DefaultAnnotationHandlerMapping and AnnotationMethodHandlerAdapter should do the trick.

answered Oct 27, 2011 at 13:12

Dejan P

4516 silver badges4 bronze badges

2 Comments

jackyesind Over a year ago

@I got null pointer exception in Object handler = handlerMapping.getHandler(request).getHandler(); How would i solve

mks-d Over a year ago

@jackyesind, as suggested in the answer the request must be initialized. Something like new MockHttpServletResponse("GET", "/your/uri");

hisdrewness · Accepted Answer · 2011-04-25 04:19:15Z

1

You can also look into other web testing frameworks that are independent of Spring like HtmlUnit, or Selenium. You won't find any more robust strategy with JUnit alone other than what Sasha has described, except you should definitely assert the model.

answered Apr 25, 2011 at 4:19

hisdrewness

7,6512 gold badges24 silver badges28 bronze badges

Collectives™ on Stack Overflow

How to unit test a Spring MVC annotated controller?

3 Answers 3

6 Comments

2 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

6 Comments

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related