出现错误时如何使用RestTemplate读取正文？

Question

I'm using RestTemplate to communicate with one REST service, i use

     restTemplate.postForEntity(uri, request, MyResponse.class);
 } catch (HttpClientErrorException e)

however when there is an error (4xx or 5xx) REST service returns description in JSON in a body, but HttpClientErrorException.getResponseBodyAsString() returns null. RestTemplate (if i try to retrieve response as String), doesn't return anything as well.

How to retrieve body in case of error?

Answer 1

You can access the response for errors via a ResponseErrorHandler . The ResponseErrorHandler needs to be set for the RestTemplate with the setErrorHandler method.

The ResponseErrorHandler provides the response via the two methods

boolean hasError(ClientHttpResponse response) throws IOException;

void handleError(ClientHttpResponse response) throws IOException;

Answer 2

Problem was recognised, it's described here https://jira.spring.io/browse/SPR-16781?focusedCommentId=159473&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-159473 and here https://jira.spring.io/browse/SPR-9367

you need to use different http library, for example Apache HttpClient (not a default one from JDK).

Add to your project:

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
</dependency>

and configure RestTemplate with:

restTemplate.setRequestFactory(new HttpComponentsClientHttpRequestFactory());

you can use ResponseErrorHandler if you need, but it's not necessary.

Now response body (even in error situation) is stored in HttpClientErrorException , read it with getResponseBodyAsString() method.