I have a ITest in Spring which looks like this:

@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class AuthControllerITest {

    @Autowired
    private TestRestTemplate template;

    @Test
    public void shouldGetAccessToken() throws Exception {
        String email = "[email protected]";
        String url = AuthController.GET_TOKEN_PATH+"?email="+email;

        ResponseEntity<AuthResponse> response = template.getForEntity(url, AuthResponse.class);

        assertThat(response.getStatusCode().is2xxSuccessful());
    }
}

But method execution causes an error

org.springframework.web.client.RestClientException: Error while extracting response for type [class com.my.app.security.ui.response.AuthResponse] and content type [application/json]

AuthResponseController action and Response model look like following:

@GetMapping(AuthController.GET_TOKEN_PATH)
public ResponseEntity<AuthResponse> auth(@RequestParam(required = false) String email)
{
    if (null == email) {
        throw new RuntimeException("Email must be provided");
    }

    User user = userRepository.findUserByEmail(email);

    return ResponseEntity.ok(new AuthResponse(jwtService.createToken(user)));
}

public class AuthResponse {
    private String token = "some token";

    public AuthResponse(String token) {
        this.token = token;
    }

    public String getToken() {
        return token;
    }
}

It works when I switch type from specific class to just a String:

ResponseEntity<String> response = template.getForEntity(url, String.class);

But I want to get AuthResponse object – besides the status code I want to check if generated token is correct.

So could you tell me why I cannot get the mapped AuthResponse object?