How to test SpringMvc controller that returns pageable result with MockMvc?

Question

Using spring-boot 2.2.4.

I have a SpringMvc Controller that returns pageable objects:

@RestController
@RequestMapping("/call-data")
public class CallDataController {
  @GetMapping
  public Page<CallDataDto> findAll(Pageable page) {
...

Trying to test it with MockMvc:

ObjectMapper mapper = new ObjectMapper();
MvcResult mvcResult = mockMvc.perform(MockMvcRequestBuilders.get("/call-data")).andReturn();
Page<CallDataDto> myDtos = mapper.readValue(mvcResult.getResponse().getContentAsString(), TypeUtils.pageTypeRef());

...

public class TypeUtils {
  public static <T> TypeReference<RestResponsePage<T>> pageTypeRef() {
      return new TypeReference<>() {
};
}

But instead of page with dto objects I get a page with LinkedHashMaps.

So how to get the page with dto objects?

score 0 · Answer 1 · answered Mar 04 '20 at 16:20

Similar question: ObjectMapper using TypeReference not working when passed type in generic method

You can solve the problem by replacing the type parameter(T) with CallDataDto.

public class TypeUtils {
  public static TypeReference<RestResponsePage<CallDataDto>> pageTypeRef() {
      return new TypeReference<>() {
};
}

Type parameters(e.g. <T>) don't exist at runtime so you have to replace them with some concrete values so that Jackson can obtain full generics type information.

How to test SpringMvc controller that returns pageable result with MockMvc?

1 Answers1