RestTemplate - Handling response headers/body in Exceptions (RestClientException, HttpStatusCodeException)

Question

In my restful webservice, in case of bad request (5xx) or 4xx respose codes, I write a custom header "x-app-err-id" to the response.

On the client side, I use exchange method of RestTemplate to make a RestFul web service call. Everything is fine when the response code is 2xx.

ResponseEntity<Component> response = restTemplate.exchange(webSvcURL,     HttpMethod.POST,      requestEntity,     Component.class); 

But if there is an exception(HttpStatusCodeException) because of it being a bad request(5xx) or 4xx, in the catch block of HttpStatusCodeException, I get response(see above) as null and so I do not have access to my custom header I set in my web service. How do I get custom headers from the response in case of exceptions in RestTemplate.

One more question is, I set an error object(json) in the reponse body in case of error and I would like to know how to access response body as well in case of exceptions in RestTemplate

Answer 1

I finally did it using ResponseErrorHandler.

public class CustomResponseErrorHandler implements ResponseErrorHandler {      private static ILogger logger = Logger.getLogger(CustomResponseErrorHandler.class);      private ResponseErrorHandler errorHandler = new DefaultResponseErrorHandler();      public void handleError(ClientHttpResponse response) throws IOException {          List<String> customHeader = response.getHeaders().get("x-app-err-id");          String svcErrorMessageID = "";         if (customHeader != null) {             svcErrorMessageID = customHeader.get(0);                         }          try {                         errorHandler.handleError(response);          } catch (RestClientException scx) {                       throw new CustomException(scx.getMessage(), scx, svcErrorMessageID);         }     }      public boolean hasError(ClientHttpResponse response) throws IOException {         return errorHandler.hasError(response);     } } 

And then use this custom response handler for RestTemplate by configuring as shown below

<bean id="restTemplate" class="org.springframework.web.client.RestTemplate">    <property name="messageConverters">        <list>            <ref bean="jsonConverter" />        </list>    </property>        <property name="errorHandler" ref="customErrorHandler" /> </bean>  <bean id="jsonConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">    <property name="supportedMediaTypes" value="application/json" /> </bean>  <bean id="customErrorHandler " class="my.package.CustomResponseErrorHandler"> </bean>