RestTemplate - 处理异常中的响应头/正文(RestClientException、HttpStatusCodeException) [英] RestTemplate - Handling response headers/body in Exceptions (RestClientException, HttpStatusCodeException)

问题描述

在我的宁静网络服务中，如果出现错误的请求 (5xx) 或 4xx 响应代码，我会向响应写入一个自定义标头x-app-err-id".

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.

在客户端，我使用 RestTemplate 的 exchange 方法进行 RestFul 网络服务调用.当响应代码为 2xx 时，一切正常.

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);

但是如果由于它是一个错误的请求(5xx)或 4xx 而出现异常(HttpStatusCodeException)，则在 HttpStatusCodeException 的 catch 块中，我得到的响应(见上文)为空，因此我无法访问我的我在 Web 服务中设置的自定义标头.如果 RestTemplate 中出现异常，如何从响应中获取自定义标头.

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.

还有一个问题是，我在响应正文中设置了一个错误对象(json)以防出错，我想知道在 RestTemplate 中出现异常时如何访问响应正文

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

推荐答案

我终于使用 ResponseErrorHandler 做到了.

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);
    }
}

然后通过如下配置为 RestTemplate 使用这个自定义响应处理程序

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>

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