ClientHttpResponse.getBody() 在响应码为 401 时抛出 ResourceAccessException

Question

我正在尝试记录每个请求的请求-响应对。问题是当响应代码为401 时，ClientHttpResponse.getBody() 会抛出 ResourceAccessException 并且我无法读取响应正文。

这是 RestTemplate 配置

RestTemplate restTemplate = new RestTemplate();

// Added this requestFactory to make response object readable more than once.
ClientHttpRequestFactory requestFactory =
        new BufferingClientHttpRequestFactory(new SimpleClientHttpRequestFactory());
restTemplate.setRequestFactory(requestFactory);
restTemplate.getInterceptors().add(new RequestLoggingInterceptor(vCloudRequest.getAction(),httpHeaders));
    restTemplate.setErrorHandler(new RequestErrorHandler());

return restTemplate;

下面拦截器的最后一行抛出如下异常。

我该如何解决这个问题？

org.springframework.web.client.ResourceAccessException: I/O 错误 “https://example.com/api/sessions”的 POST 请求：服务器返回 HTTP 响应代码：401 用于 URL：https://example.com/api/sessions； 嵌套异常是 java.io.IOException：服务器返回 HTTP 响应 代码：401 用于 URL：https://example.com.11/api/sessions

这是拦截器的相关部分。

@Override
public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
    ClientHttpResponse response = execution.execute(request, body);

    String requestString = new String(body);

    // Calling this method because when we make a POST or PUT request and get an error
    // response.getBody() throws IOException. But if we call response.getStatusCode() it works fine.
    // I don't know the reason.
    // I asked a question on stackoverflow
    // https://stackoverflow.com/questions/47429978/resttemplate-response-getbody-throws-exception-on-4-and-5-errors-for-put-and
    response.getStatusCode();
    String responseString = new String(ByteStreams.toByteArray(response.getBody()), Charset.forName("UTF-8"));
...
}

这是自定义错误处理程序

公共类 RequestErrorHandler 实现 ResponseErrorHandler {

@Override
public boolean hasError(ClientHttpResponse response) throws IOException {
        if (!response.getStatusCode().is2xxSuccessful()) {
        return true;
    }
    return false;
}

@Override
public void handleError(ClientHttpResponse response) throws IOException {
    JAXBElement<ErrorType> root = null;

    try {
        JAXBContext jaxbContext = JAXBContext.newInstance(ErrorType.class);
        Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();

        root = jaxbUnmarshaller.unmarshal(new StreamSource(
                response.getBody()), ErrorType.class);
    } catch (JAXBException e) {
        throw new IOException("XML converting error. Cannot convert response to ErrorType");
    }

    ErrorType error = root.getValue();
    throw new VcloudException(error);
}
}

Answer 1

使用 HttpComponentsClientHttpRequestFactory 代替 SimpleClientHttpRequestFactory。

同时添加对 'org.apache.httpcomponents:httpclient 的依赖。

当状态为 401 时，HttpComponentsClientHttpRequestFactory 可以读取正文。

Answer 2

我不认为ResourceAccessException 被response.getBody() 抛出，而是ByteStreams.toByteArray(...) 可能正在发送null 流作为响应。

如果response.getBody() 是null 或者它是ByteStreams.toByteArray()，您能否尝试调试。因为发生 I/O 错误时会抛出RescourceAccessException。

Answer 3

当 httpstatus 不是 200 时，Spring RestTemplate 默认会生成错误。

在我过去的项目中，我所做的是将自定义 org.springframework.web.client.ResponseErrorHandler 添加到其余模板中。 你可以这样写一个类：

public class SimpleRestErrorHandler implements ResponseErrorHandler
{
    private static final Logger logger = LoggerFactory.getLogger(SimpleRestErrorHandler.class.getName());
    @Override
    public boolean hasError(ClientHttpResponse response) throws IOException
    {
        int statusCode = response.getStatusCode().value();
        if( logger.isDebugEnabled() )
        {

            logger.debug("STATUS CODE ["+statusCode+"] ");
        }
        //Generate Error only when HTTP Status code is 500
        if( statusCode == 500 )
        {

            return true;
        }
        return false;
    }

    @Override
    public void handleError(ClientHttpResponse response) throws IOException
    {
      //Here you can manage the error (in this sample only the http status code = 500
    }

}

然后我将此添加到我的休息模板中：

XML 配置示例

<bean id="restTemplate" class="org.springframework.web.client.RestTemplate">        <constructor-arg ref="bufferingClientHttpRequestFactory" />         <property name="errorHandler" ref="simpleRestErrorHandler" />       <property name="messageConverters">             <list>
                <bean
                    class="org.springframework.http.converter.StringHttpMessageConverter">
                    <constructor-arg value="#{T(java.nio.charset.Charset).forName('UTF-8')}" />
                </bean>
                <bean
                    class="org.springframework.http.converter.ByteArrayHttpMessageConverter" />
                <bean
                    class="org.springframework.http.converter.ResourceHttpMessageConverter" />
                <bean
                    class="org.springframework.http.converter.xml.SourceHttpMessageConverter" />
                <bean
                    class="org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter" />
                <bean
                    class="org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter" />
                <bean
                    class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" />
                <bean
                    class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" />          </list>         </property>         <property name="interceptors">          <!-- Custom interceptors -->        </property>     </bean> <bean id="bufferingClientHttpRequestFactory" name="bufferingClientHttpRequestFactory"       class="org.springframework.http.client.BufferingClientHttpRequestFactory">      <constructor-arg ref="simpleReqFact" />     </bean> <bean id="simpleRestErrorHandler" class="handlers.SimpleRestErrorHandler" />

Java 配置

@Config
public class restTemplConfig {
 @Bean
 public RestTemplate restTempl() {
  RestTemplate result = new RestTemplate();
  //Add converters
  //Add custom error handler
  result.setErrorHandler(new SimpleRestErrorHandler());
 }
}

希望对你有用