unable to get the response entity from an api with mockmvc - spring-boot

Question

I have an issue when I try to run my controller's unit test class. I get always a empty body in the response and I don't manage to find why.
I put here the code. Maybe someone with an external vision will be able to see the reason.
the controller:
#ResponseBody
#PostMapping(path = "/upload", consumes = { MediaType.MULTIPART_FORM_DATA_VALUE }, produces = { MediaType.APPLICATION_JSON_VALUE })
public ResponseEntity<Object> uploadFile(#RequestParam("file") MultipartFile multipartFileData, #RequestParam(name="jobId", required = false) String jobId) {
JobStatus result;
try {
result = this.fileService.uploadFileChunk(multipartFileData, 1, 1, jobId);
}catch (ExecutionException|InterruptedException|IOException ex){
Thread.currentThread().interrupt();
return new ResponseEntity<>(ex,HttpStatus.INTERNAL_SERVER_ERROR);
}
return new ResponseEntity<>(result,HttpStatus.OK);
}
the unit test class:
#RunWith(SpringRunner.class)
#SpringBootTest(classes= FileUploadServiceRestController.class)
public class FileUploadServiceControllerTest {
private MockMvc mockMvc;
#Autowired
private WebApplicationContext context;
#MockBean
private FileUploadServiceImpl fileService;
#Before
public void setup() {
mockMvc = MockMvcBuilders.webAppContextSetup(context).build();
}
#Test
public void testUploadFile()
throws Exception {
MockMultipartFile file
= new MockMultipartFile(
"file",
"hello.txt",
MediaType.TEXT_PLAIN_VALUE,
"Hello, World!".getBytes()
);
JobStatus job = new JobStatus("uuid", ConstantUtil.JOB_STARTED);
when(fileService.uploadFileChunk(Mockito.any(MultipartFile.class),Mockito.eq(1),Mockito.eq(1),Mockito.isNull())).thenReturn(job);
mockMvc.perform(MockMvcRequestBuilders.multipart("/file/upload").file(file))
.andDo(MockMvcResultHandlers.print())
.andExpect(status().isOk());
}
}
and the object which will be transfered:
public class JobStatus implements Serializable {
private static final long serialVersionUID = -4405865740177389860L;
private String jobId;
private String status;
public JobStatus() {
}
public JobStatus(String jobId, String status) {
this.jobId = jobId;
this.status = status;
}
public String getJobId() {
return jobId;
}
public void setJobId(String jobId) {
this.jobId = jobId;
}
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
}
For information, this controller works well when I call it from the client. I can see that the mock is well returned when I put a breakpoint at the end of the controller, but the response body stay empty.
I add here the result of print if it could help:
MockHttpServletRequest:
HTTP Method = POST
Request URI = /file/upload
Parameters = {}
Headers = [Content-Type:"multipart/form-data"]
Body = <no character encoding set>
Session Attrs = {}
Handler:
Type = org.iso.fileservice.controller.FileUploadServiceRestController
Method = org.iso.fileservice.controller.FileUploadServiceRestController#uploadFile(MultipartFile, String)
Async:
Async started = false
Async result = null
Resolved Exception:
Type = org.springframework.http.converter.HttpMessageNotWritableException
ModelAndView:
View name = null
View = null
Model = null
FlashMap:
Attributes = null
MockHttpServletResponse:
Status = 500
Error message = null
Headers = []
Content type = null
Body =
Forwarded URL = null
Redirected URL = null
Cookies = []
thanks, Mathieu

Answer 1

Just ran into this today.
I found the answer on Why MockMvc request retrieve empty responseBody while test succeed?
I just added My restController with #Autowired instead of #InjectMocks, after that I started to retrieve the Response Entity instead of a 500 status response