java.lang.AssertionError: Content type not set - Spring Controller Junit Tests

Question

I am trying to do some unit testing on my controllers. No matter what I do all controller tests return

java.lang.AssertionError: Content type not set

I am testing that the methods return json and xml data.

Here is an example of the controller:

@Controller
@RequestMapping("/mypath")

public class MyController {

   @Autowired
   MyService myService;

   @RequestMapping(value="/schema", method = RequestMethod.GET)
   public ResponseEntity<MyObject> getSchema(HttpServletRequest request) {

       return new ResponseEntity<MyObject>(new MyObject(), HttpStatus.OK);

   }

}

The unit test is set up like this:

public class ControllerTest() { 

private static final String path = "/mypath/schema";
private static final String jsonPath = "$.myObject.val";
private static final String defaultVal = "HELLO";

MockMvc mockMvc;

@InjectMocks
MyController controller;

@Mock
MyService myService;

@Before
public void setup() {
    MockitoAnnotations.initMocks(this);

    mockMvc = standaloneSetup(controller)
                .setMessageConverters(new MappingJackson2HttpMessageConverter(),
                        new Jaxb2RootElementHttpMessageConverter()).build();


    when(myService.getInfo(any(String.class))).thenReturn(information);
    when(myService.getInfo(any(String.class), any(Date.class))).thenReturn(informationOld);

}

@Test
public void pathReturnsJsonData() throws Exception {

    mockMvc.perform(get(path).contentType(MediaType.APPLICATION_JSON))
        .andDo(print())
        .andExpect(content().contentTypeCompatibleWith(MediaType.APPLICATION_JSON))
        .andExpect(jsonPath(jsonPath).value(defaultVal));
}

}

I am using: Spring 4.0.2 Junit 4.11 Gradle 1.12

I have seen the SO question Similiar Question but no matter what combination of contentType and expect in my unit test I get the same result.

Any help would be much appreciated.

Thanks

Answer 1

Your solution depends on what kinds of annotation you want to use in your project.

• You can add @ResponseBody to your getSchema method in Controller

• Or, maybe adding produces attribute in your @RequestMapping can solve it too.

  @RequestMapping(value="/schema", 
        method = RequestMethod.GET, 
        produces = {MediaType.APPLICATION_JSON_VALUE} )
  

• Final choice, add headers to your ResponseEntity (which is one of the main objective of using this class)

  //...
  HttpHeaders headers = new HttpHeaders();
  headers.add("Content-Type", "application/json; charset=utf-8");
  return new ResponseEntity<MyObject>(new MyObject(), headers, HttpStatus.OK);
  

Edit : I've just seen you want Json AND Xml Data, so the better choice would be the produces attribute:

@RequestMapping(value="/schema", 
      method = RequestMethod.GET, 
      produces = {MediaType.APPLICATION_JSON_VALUE, MediaType.APPLICATION_XML_VALUE} )