Using the curl command:
curl -u 591bf65f50057469f10b5fd9:0cf17f9b03d056ds0e11e48497e506a2 https://backend.tdk.com/api/devicetypes/59147fd79e93s12e61499ffe/messages
I am getting a JSON response:
{"data":[{"device":"18SE62","time":1494516023,"data":"3235","snr":"36.72",...
I save the response on a txt file and parse it using jackson, and everything is fine
ObjectMapper mapper = new ObjectMapper();
File f = new File(getClass().getResource
("/result.json").getFile());
MessageList messageList = mapper.readValue(f, MessageList.class);
and I assume I should get the same result using RestTemplate but that's not the case
RestTemplate restTemplate = new RestTemplate();
MessageList messageList =
restTemplate.getForObject("http://592693f43c87815f9b8145e9:f099c85d84d4e325a2186c02bd0caeef#backend.tdk.com/api/devicetypes/591570373c87894b4eece34d/messages", MessageList.class);
I got an error instead
Exception in thread "main" org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [class com.tdk.domain.backend.MessageList] and content type [text/html;charset=iso-8859-1]
at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:109)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:655)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:613)
at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:287)
at com.tdk.controllers.restful.client.RestTemplateExample.main(RestTemplateExample.java:27)
I tried to set the contentType:
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
HttpEntity<String> entity = new HttpEntity<String>("parameters", headers);
MessageList messageList =
restTemplate.getForObject(url, entity, MessageList.class);
but then I got a compilation error
The method getForObject(String, Class<T>, Object...) in the type RestTemplate is not applicable for the arguments (String, HttpEntity<String>,
Class<MessageList>)
I also tried to add a the Jackson Message converter
List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
//Add the Jackson Message converter
messageConverters.add(new MappingJackson2HttpMessageConverter());
//Add the message converters to the restTemplate
restTemplate.setMessageConverters(messageConverters);
MessageList messageList =
restTemplate.getForObject(url, MessageList.class);
But then I got this error:
Exception in thread "main" org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [class com.tdk.domain.backend.MessageList] and content type [text/html;charset=iso-8859-1]
at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:109)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:655)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:613)
at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:287)
at com.tdk.controllers.restful.client.RestTemplateExample.main(RestTemplateExample.java:51)
I also tried adding the class
#Configuration
#EnableWebMvc
public class MvcConf extends WebMvcConfigurationSupport {
protected void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
converters.add(converter());
addDefaultHttpMessageConverters(converters);
}
#Bean
MappingJackson2HttpMessageConverter converter() {
MappingJackson2HttpMessageConverter converter
= new MappingJackson2HttpMessageConverter();
return converter;
}
}
but I got the error:
org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [class com.tdk.domain.backend.MessageList] and content type [text/html;charset=iso-8859-1]
at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:109)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:655)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:613)
at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:287)
The main problem here is content type [text/html;charset=iso-8859-1] received from the service, however the real content type should be application/json;charset=iso-8859-1
In order to overcome this you can introduce custom message converter. and register it for all kind of responses (i.e. ignore the response content type header). Just like this
List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
//Add the Jackson Message converter
MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
// Note: here we are making this converter to process any kind of response,
// not only application/*json, which is the default behaviour
converter.setSupportedMediaTypes(Collections.singletonList(MediaType.ALL));
messageConverters.add(converter);
restTemplate.setMessageConverters(messageConverters);
While the accepted answer solved the OP's original problem, most people finding this question through a Google search are likely having an entirely different problem which just happens to throw the same no suitable HttpMessageConverter found exception.
What happens under the covers is that MappingJackson2HttpMessageConverter swallows any exceptions that occur in its canRead() method, which is supposed to auto-detect whether the payload is suitable for json decoding. The exception is replaced by a simple boolean return that basically communicates sorry, I don't know how to decode this message to the higher level APIs (RestClient). Only after all other converters' canRead() methods return false, the no suitable HttpMessageConverter found exception is thrown by the higher-level API, totally obscuring the true problem.
For people who have not found the root cause (like you and me, but not the OP), the way to troubleshoot this problem is to place a debugger breakpoint on onMappingJackson2HttpMessageConverter.canRead(), then enable a general breakpoint on any exception, and hit Continue. The next exception is the true root cause.
My specific error happened to be that one of the beans referenced an interface that was missing the proper deserialization annotations.
UPDATE FROM THE FUTURE
This has proven to be such a recurring issue across so many of my projects, that I've developed a more proactive solution. Whenever I have a need to process JSON exclusively (no XML or other formats), I now replace my RestTemplate bean with an instance of the following:
public class JsonRestTemplate extends RestTemplate {
public JsonRestTemplate(
ClientHttpRequestFactory clientHttpRequestFactory) {
super(clientHttpRequestFactory);
// Force a sensible JSON mapper.
// Customize as needed for your project's definition of "sensible":
ObjectMapper objectMapper = new ObjectMapper()
.registerModule(new Jdk8Module())
.registerModule(new JavaTimeModule())
.configure(
SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
List<HttpMessageConverter<?>> messageConverters = new ArrayList<>();
MappingJackson2HttpMessageConverter jsonMessageConverter = new MappingJackson2HttpMessageConverter() {
public boolean canRead(java.lang.Class<?> clazz,
org.springframework.http.MediaType mediaType) {
return true;
}
public boolean canRead(java.lang.reflect.Type type,
java.lang.Class<?> contextClass,
org.springframework.http.MediaType mediaType) {
return true;
}
protected boolean canRead(
org.springframework.http.MediaType mediaType) {
return true;
}
};
jsonMessageConverter.setObjectMapper(objectMapper);
messageConverters.add(jsonMessageConverter);
super.setMessageConverters(messageConverters);
}
}
This customization makes the RestClient incapable of understanding anything other than JSON. The upside is that any error messages that may occur will be much more explicit about what's wrong.
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>
One way to debug this issue is to first take the response as a String.class and then use
Gson().fromJson(StringResp.body(), MyDTO.class)
It will most likely still fail, but this time it will throw the fields that caused the error in the first place. Following the modification, we can resume using the previous approach as before.
ResponseEntity<String> respStr = restTemplate.exchange(URL,HttpMethod.GET, entity, String.class);
Gson g = new Gson();
The following step will generate an error with the fields that are causing the problem.
MyDTO resp = g.fromJson(respStr.getBody(), MyDTO.class);
I don't have the error message with me, but it will point to the problematic field and explain why. Resolve those and try the previous approach again.
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);
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
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);
This way you can get the object response using resttemplate and set contentType using MediaType.APPLICATION_JSON
public List<Employee> getListofEmployee()
{
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity<String> entity = new HttpEntity<String>(headers);
ResponseEntity<List<Employee>> response = restTemplate.exchange("http://hello-server/rest/employees",
HttpMethod.GET,entity, new ParameterizedTypeReference<List<Employee>>() {});
return response.getBody(); //this returns List of Employee
}
Please add the shared dependency having jackson databind package . Hope this will clear the issue.
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.12.1</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.
Spring sets the default content-type to octet-stream when the response is missing that field. All you need to do is to add a message converter to fix this.
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 trying to use Feign, while I encounter same issue, As I understood HTTP message converter will help but wanted to understand how to achieve this.
#FeignClient(name = "mobilesearch", url = "${mobile.search.uri}" ,
fallbackFactory = MobileSearchFallbackFactory.class,
configuration = MobileSearchFeignConfig.class)
public interface MobileSearchClient {
#RequestMapping(method = RequestMethod.GET)
List<MobileSearchResponse> getPhones();
}
You have to use Customer Configuration for the decoder, MobileSearchFeignConfig,
public class MobileSearchFeignConfig {
#Bean
Logger.Level feignLoggerLevel() {
return Logger.Level.FULL;
}
#Bean
public Decoder feignDecoder() {
return new ResponseEntityDecoder(new SpringDecoder(feignHttpMessageConverter()));
}
public ObjectFactory<HttpMessageConverters> feignHttpMessageConverter() {
final HttpMessageConverters httpMessageConverters = new HttpMessageConverters(new MappingJackson2HttpMessageConverter());
return new ObjectFactory<HttpMessageConverters>() {
#Override
public HttpMessageConverters getObject() throws BeansException {
return httpMessageConverters;
}
};
}
public class MappingJackson2HttpMessageConverter extends org.springframework.http.converter.json.MappingJackson2HttpMessageConverter {
MappingJackson2HttpMessageConverter() {
List<MediaType> mediaTypes = new ArrayList<>();
mediaTypes.add(MediaType.valueOf(MediaType.TEXT_HTML_VALUE + ";charset=UTF-8"));
setSupportedMediaTypes(mediaTypes);
}
}
}
In my case i was missing the No Args contructor
#Data
#AllArgsConstructor
#NoArgsConstructor
for those who are no using Lombok do add no args constructor in the mapping pojo
public ClassA() {
super();
// TODO Auto-generated constructor stub
}
also dont forget to add the Bean of Restemplate in main file if you are using the same
Infuriating problem right?
You just wanna get the result of the call, and you have a deSerialization error...that you have no clue where to look for.
Well, all is not lost.
If you change the type of call to String, you can get the JSON equivalent and then write a test to see why it is not serializing:
RestTemplate restTemplate = new RestTemplate();
String messageListString = restTemplate.getForObject("http://592693f43c87815f9b8145e9:f099c85d84d4e325a2186c02bd0caeef#backend.tdk.com/api/devicetypes/591570373c87894b4eece34d/messages", String.class);
Here is an example with an input param I used in my Kotlin project:
fun givenCUT_whenFetchingBillableItemsForAPastMonthWithoutBillingData_thenWeSucceedInGettingAnEmptyXmlResponse() {
val restTemplate = RestTemplate()
val uri = "http://localhost:$port/api/test/billing/xml/month/{month}/"
val params: MutableMap<String, String> = HashMap()
params["month"] = "2022-09-01"
val stringResponse = restTemplate.getForObject(uri, String::class.java, params)
assertNotNull(stringResponse)
assertEquals("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>\n" +
"<bi:billableItems xmlns:bi=\"urn:blahblahblah\"/>\n", stringResponse)
}
If you step through that test, and harvest the actual JSON of your endpoint, you can then use a test like this, to pump it in, and see why Jackson or Gson is complains:
#Test
fun givenCUT_whenDeSerializingBEStateCorrectionsResponse_thenWeGetAnInstanceOfAListOfBillingOrdersSuccessfully() {
//Raw JSON harvested from BillingOrderControllerTest
val harvestedFEJsonBillingOrderList = "YOUR JSON Harvested from above goes here"
val mapper = ObjectMapper()
mapper.registerModule(JavaTimeModule())
mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
val deSerBillingOrderList = mapper.readValue(harvestedFEJsonBillingOrderList, Array<BillingOrder>::class.java)
assertNotNull(deSerBillingOrderList)
assertEquals(1, deSerBillingOrderList.size)
}
The post is just as easy...the following is a snippet but you can see I finally gave up and commented out the serialization error part, and reverted to the String version and did the necessary with the test above in Jackson; I just this minute did that, and found 4 issues in the de-serialized JSON that Jackson explicitly reported on, and that I will fix. Then, I will revert the below to the typed version and it should have solved the problem:
try {
val result = restTemplate!!.postForEntity(uri, billingOrders, String::class.java)
/* val result = restTemplate!!.postForObject(
baseUrl,
billingOrders,
ResponseEntity<List<BillingOrder>>::class.java)*/
assertNotNull(result)
} catch (e: Exception) {
log.error("Failed restTemplate.postForObject with $e")
}
I have a JAX-RS web service that returns a Response object as shown below (it is running in WebLogic 12.2.1). It will return a JSON response to the client. Is it possible to write an interceptor or filter, such that when the web service call is returned, it will add an extra field in the JSON response?
#POST
#Consumes(MediaType.APPLICATION_JSON)
#Produces(MediaType.APPLICATION_JSON)
#Path("LogIn")
public Response logIn(#Context HttpServletRequest request, Parameters requestParameters) {...}
Thanks in advance.
If using Jersey, then you can try implementing ContainerResponseFilter.
On Over-riding filter(), it provides ContainerResponseContext object which gives you access to the response that is being sent using getEntity() method.
You can modify this object and set it back in the response.
public class ResponseInterceptor implements ContainerResponseFilter{
#Override
public void filter(ContainerRequestContext requestContext, ContainerResponseContext responseContext)
throws IOException {
Object obj = responseContext.getEntity();
// Modify the Response obj as per need
responseContext.setEntity(obj);
}
}
I am new to this #ExceptionHandler. I need to return response in JSON format if there is any exception. My code is returning response in JSON format if the operation is successful. But when any exception is thrown it is return HTML response as I have used #ExceptionHandler.
Value and reason in #ResponseStatus is coming properly but in HTML. How can I can change it to a JSON response? Please help.
In my controller class i have this methods:
#RequestMapping(value = "/savePoints", method = RequestMethod.POST, consumes = "application/json", produces = "application/json;charset=UTF-8")
public #ResponseBody
GenericResponseVO<TestResponseVO> saveScore(
#RequestBody(required = true) GenericRequestVO<TestVO> testVO) {
UserContext userCtx = new UserContext();
userCtx.setAppId("appId");
return gameHandler.handle(userCtx, testVO);
}
Exception handling method:
#ResponseStatus(value = HttpStatus.NOT_FOUND, reason = "Error in the process")
#ExceptionHandler(Exception.class)
public void handleAllOtherException() {
}
You can annotate the handler method with #ResponseBody and return any object you want and it should be serialized to JSON (depending on your configuration of course). For instance:
public class Error {
private String message;
// Constructors, getters, setters, other properties ...
}
#ResponseBody
#ResponseStatus(HttpStatus.BAD_REQUEST)
#ExceptionHandler(MethodArgumentNotValidException.class)
public Error handleValidationException(MethodArgumentNotValidException e) {
// Optionally do additional things with the exception, for example map
// individual field errors (from e.getBindingResult()) to the Error object
return new Error("Invalid data");
}
which should produce response with HTTP 400 code and following body:
{
"message": "Invalid data"
}
Also see Spring JavaDoc for #ExceptionHandler which lists possible return types, one of which is:
#ResponseBody annotated methods (Servlet-only) to set the response content. The return value will be converted to the response stream using message converters.
Replace
#ResponseStatus(value = HttpStatus.NOT_FOUND, reason = "Error in the process")
by
#ResponseStatus(value = HttpStatus.NOT_FOUND)
the 'reason' attribute force html render!
I've waste 1 day on that.....
I have created a rest webservice which has a below code in one method:
#POST
#Path("/validUser")
#Consumes(MediaType.APPLICATION_JSON)
#Produces(MediaType.APPLICATION_JSON)
public JSONObject validUserLogin(#QueryParam(value="userDetails") String userDetails){
JSONObject json = null;
try{
System.out.println("Service running from validUserLogin :"+userDetails);
json = new JSONObject(userDetails);
System.err.println("UserName : "+json.getString("userName")+" password : "+json.getString("password"));
json.put("httpStatus","OK");
return json;
}
catch(JSONException jsonException) {
return json;
}
}
I am using Apache API in the client code.And below client code is calling this service, by posting some user related data to this service:
public static String getUserAvailability(String userName){
JSONObject json=new JSONObject();
try{
HttpContext context = new BasicHttpContext();
HttpClient client = new DefaultHttpClient();
client.getParams().setParameter(ClientPNames.COOKIE_POLICY, CookiePolicy.RFC_2109);
URI uri=new URIBuilder(BASE_URI+PATH_VALID_USER).build();
HttpPost request = new HttpPost(uri);
request.setHeader("Content-Type", "application/json");
json.put("userName", userName);
StringEntity stringEntity = new StringEntity(json.toString());
request.setEntity(stringEntity);
HttpResponse response = client.execute(request,context);
System.err.println("content type : \n"+EntityUtils.toString(response.getEntity()));
}catch(Exception exception){
System.err.println("Client Exception: \n"+exception.getStackTrace());
}
return "OK";
}
The problem is, I am able to call the service, but the parameter I passed in the request to service results in null.
Am I posting the data in a wrong way in the request. Also I want to return some JSON data in the response, but I am not able to get this.
With the help of Zack , some how i was able to resolve the problem,
I used jackson-core jar and changed the service code as below.
#POST
#Path("/validUser")
#Consumes(MediaType.APPLICATION_JSON)
#Produces(MediaType.APPLICATION_JSON)
public JSONObject validUserLogin(String userDetails){
ObjectMapper mapper = new ObjectMapper();
JsonNode node = mapper.readValue(userDetails, JsonNode.class);
System.out.println("Service running from validUserLogin :"+userDetails);
System.out.println(node.get("userName").getTextValue());
//node.("httpStatus","OK");
return Response.ok(true).build();
}
I tried to find how I can write in Spring to POST JSON from REST client. For example, I wrote:
#RequestMapping(value = "/{userId}/add", method = RequestMethod.POST, headers = {"content-type=application/json"})
#ResponseBody
public Map<String, String> saveUser(#RequestBody User user, BindingResult result) {
Map<String, String> jsonResponse = new HashMap<String, String>();
if (result.hasErrors()) {
jsonResponse.put("Message", "Can't add the user");
jsonResponse.put("Code", "401");
return jsonResponse;
}
userService.addUser(user);
jsonResponse.put("Message", "Success add User");
jsonResponse.put("Code", "200");
return jsonResponse;
}
End tested it from Firefox REST client. But I saw 404 error. What am I doing wrong? Thanx for help.
First, if the URI of your request ended with "/user/2/add", it won't map to your method, which is mapped as "/{userId}/add". This will cause the HTTP 404 error you receive. Instead, your URI should end with "/2/add", if the "userId" is 2.
Second, annotating the User parameter with #RequestBody is not enough for the complex User type. You will need to convert your JSON request body into a User object. You can accomplish this with the MappingJacksonHttpMessageConverter. By declaring a bean of this type, you can use Jackson's annotations to control how the JSON is parsed into the User properties.