"Could not find acceptable representation" when testing spring download link with MockMvc - spring

Question

I have a controller that should allow downloading files with arbitrary content type:
#GetMapping(value="/download/{directory}/{name}",
consumes=MediaType.ALL_VALUE)
#Timed
public ResponseEntity<byte[]> downloadFile(#PathVariable String directory,
#PathVariable String name) {
log.debug("REST request to download File : {}/{}", directory, name);
byte[] content = "it works".getBytes();
HttpHeaders headers = new HttpHeaders();
headers.add(HttpHeaders.CONTENT_TYPE, "text/plain");
return new ResponseEntity<>(content, headers, HttpStatus.OK);
}
I want to test that in a unit test like this:
...
private MockMvc restFileMockMvc;
#Before
public void setup() {
MockitoAnnotations.initMocks(this);
final FileResource fileResource = new FileResource(fileService);
this.restFileMockMvc = MockMvcBuilders.standaloneSetup(fileResource)
.setCustomArgumentResolvers(pageableArgumentResolver)
.setControllerAdvice(exceptionTranslator)
.setConversionService(createFormattingConversionService())
.setMessageConverters(jacksonMessageConverter)
.setValidator(validator).build();
}
#Test
#Transactional
public void downloadFile() throws Exception {
String url = "/api/download/it/works.txt";
restFileMockMvc.perform(get(url).header(HttpHeaders.ACCEPT, "*/*"))
.andDo(MockMvcResultHandlers.print()) // Debugging only!
.andExpect(status().isOk());
}
But obviously, there is a problem with the content type, resp. the accept header. MockMvcResultHandlers.print() produces the following:
MockHttpServletRequest:
HTTP Method = GET
Request URI = /api/download/DIRDIR/NAMENAME
Parameters = {}
Headers = {Accept=[*/*]}
Body = <no character encoding set>
Session Attrs = {}
Handler:
Type = com.example.storage.web.rest.FileResource
Method = public org.springframework.http.ResponseEntity<byte[]> com.example.storage.web.rest.FileResource.downloadFile(java.lang.String,java.lang.String)
Async:
Async started = false
Async result = null
Resolved Exception:
Type = org.springframework.web.HttpMediaTypeNotAcceptableException
ModelAndView:
View name = null
View = null
Model = null
FlashMap:
Attributes = null
MockHttpServletResponse:
Status = 406
Error message = null
Headers = {Content-Type=[application/problem+json]}
Content type = application/problem+json
Body = {"type":"https://www.jhipster.tech/problem/problem-with-message","title":"Not Acceptable","status":406,"detail":"Could not find acceptable representation","path":"/api/download/DIRDIR/NAMENAME","message":"error.http.406"}
Forwarded URL = null
Redirected URL = null
Cookies = []
It looks like the request is sent with Accept: */*. What does Spring complain about then?

Answer 1

It could be an issue with your message converter, used in your test case. I too faced similar issue and resolved it by passing additional parameter in messageConverter for my mockMvc
this.restMockMvc = MockMvcBuilders.standaloneSetup(testResource)
.setCustomArgumentResolvers(pageableArgumentResolver)
.setControllerAdvice(exceptionTranslator)
.setMessageConverters(jacksonMessageConverter,new
ByteArrayHttpMessageConverter()).build();
You need to overload message converter property for MockMVC. for more info , relevant question

Answer 2

I was already using #SpringJUnitWebConfig(...) and included the #EnableWebMvc annotation to my imported Config. This seemed to add all the necessary converters. E.g.
#SpringJUnitWebConfig(MyTestConfig.class)
class MyTest {
#Inject
private WebApplicationContext wac;
private MockMvc mockMvc;
...
}
#EnableWebMvc
class MyTestConfig {
#Bean
...
}