Using the curl command:
curl -u 591bf65f50057469f10b5fd9:0cf17f9b03d056ds0e11e48497e506a2 https://backend.tdk.com/api/devicetypes/59147fd79e93s12e61499ffe/me
In my case @Ilya Dyoshin's solution didn't work: The mediatype "*" was not allowed. I fix this error by adding a new converter to the restTemplate this way during initialization of the MockRestServiceServer:
MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter =
new MappingJackson2HttpMessageConverter();
mappingJackson2HttpMessageConverter.setSupportedMediaTypes(
Arrays.asList(
MediaType.APPLICATION_JSON,
MediaType.APPLICATION_OCTET_STREAM));
restTemplate.getMessageConverters().add(mappingJackson2HttpMessageConverter);
mockServer = MockRestServiceServer.createServer(restTemplate);
(Based on the solution proposed by Yashwant Chavan on the blog named technicalkeeda)
JN Gerbaux
If the above response by @Ilya Dyoshin didn't still retrieve, try to get the response into a String Object.
(For my self thought the error got solved by the code snippet by Ilya, the response retrieved was a failure(error) from the server.)
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.add(HttpHeaders.CONTENT_TYPE, "application/x-www-form-urlencoded");
ResponseEntity<String> st = restTemplate.exchange(url, HttpMethod.POST, httpEntity, String.class);
And Cast to the ResponseObject DTO (Json)
Gson g = new Gson();
DTO dto = g.fromJson(st.getBody(), DTO.class);
Other possible solution : I tried to map the result of a restTemplate.getForObject with a private class instance (defined inside of my working class). It did not work, but if I define the object to public, inside its own file, it worked correctly.
I was having a very similar problem, and it turned out to be quite simple; my client wasn't including a Jackson dependency, even though the code all compiled correctly, the auto-magic converters for JSON weren't being included. See this RestTemplate-related solution.
In short, I added a Jackson dependency to my pom.xml and it just worked:
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.5.1</version>
</dependency>
In my case it was caused by the absence of the jackson-core, jackson-annotations and jackson-databind jars from the runtime classpath. It did not complain with the usual ClassNothFoundException as one would expect but rather with the error mentioned in the original question.
You need to create your own converter and implement it before making a GET request.
RestTemplate restTemplate = new RestTemplate();
List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
converter.setSupportedMediaTypes(Collections.singletonList(MediaType.ALL));
messageConverters.add(converter);
restTemplate.setMessageConverters(messageConverters);