我已经使用Spring RestTemplate有一段时间了,当我试图调试它的请求和响应时,我总是碰壁。我基本上希望看到与打开“verbose”选项时使用curl时相同的东西。例如:

curl -v http://twitter.com/statuses/public_timeline.rss

将显示发送的数据和接收的数据(包括头、cookie等)。

我看了一些相关的帖子,比如: 如何在Spring RestTemplate中记录响应? 但我还没能解决这个问题。

实现这一点的一种方法是实际更改RestTemplate源代码,并在那里添加一些额外的日志记录语句,但我认为这种方法确实是最后的办法。应该有某种方法告诉Spring Web Client/RestTemplate以一种更友好的方式记录所有内容。

我的目标是能够用如下代码做到这一点:

restTemplate.put("http://someurl", objectToPut, urlPathValues);

然后在日志文件或控制台中获得相同类型的调试信息(就像我使用curl获得的一样)。 我相信这对于任何使用Spring RestTemplate并且遇到问题的人来说都是非常有用的。使用curl来调试RestTemplate问题是行不通的(在某些情况下)。


当前回答

除了上面的讨论,这只代表了快乐的场景。如果出现错误,您可能无法记录响应。

在这种情况下加上上面所有的情况,您必须重写DefaultResponseErrorHandler并像下面那样设置它

restTemplate.setErrorHandler(new DefaultResponseErrorHandlerImpl());

其他回答

用ClientHttpRequestInterceptor的完整实现来完成这个示例,以跟踪请求和响应:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;

public class LoggingRequestInterceptor implements ClientHttpRequestInterceptor {

    final static Logger log = LoggerFactory.getLogger(LoggingRequestInterceptor.class);

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

    private void traceRequest(HttpRequest request, byte[] body) throws IOException {
        log.info("===========================request begin================================================");
        log.debug("URI         : {}", request.getURI());
        log.debug("Method      : {}", request.getMethod());
        log.debug("Headers     : {}", request.getHeaders() );
        log.debug("Request body: {}", new String(body, "UTF-8"));
        log.info("==========================request end================================================");
    }

    private void traceResponse(ClientHttpResponse response) throws IOException {
        StringBuilder inputStringBuilder = new StringBuilder();
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(response.getBody(), "UTF-8"));
        String line = bufferedReader.readLine();
        while (line != null) {
            inputStringBuilder.append(line);
            inputStringBuilder.append('\n');
            line = bufferedReader.readLine();
        }
        log.info("============================response begin==========================================");
        log.debug("Status code  : {}", response.getStatusCode());
        log.debug("Status text  : {}", response.getStatusText());
        log.debug("Headers      : {}", response.getHeaders());
        log.debug("Response body: {}", inputStringBuilder.toString());
        log.info("=======================response end=================================================");
    }

}

然后使用BufferingClientHttpRequestFactory和LoggingRequestInterceptor实例化RestTemplate:

RestTemplate restTemplate = new RestTemplate(new BufferingClientHttpRequestFactory(new SimpleClientHttpRequestFactory()));
List<ClientHttpRequestInterceptor> interceptors = new ArrayList<>();
interceptors.add(new LoggingRequestInterceptor());
restTemplate.setInterceptors(interceptors);

BufferingClientHttpRequestFactory是必需的,因为我们想在拦截器和初始调用代码中使用响应体。默认实现只允许读取响应体一次。

我浏览了所有的答案,如果你需要设置认证类型或连接超时,那么你可以这样做:

SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
factory.setConnectTimeout(Integer.valueOf(YOUR_VALUE));
factory.setReadTimeout(Integer.valueOf(YOUR_VALUE));

RestTemplate restTemplate = new RestTemplate(new BufferingClientHttpRequestFactory(factory));
restTemplate.getInterceptors().add(new LoggingRequestInterceptor());
restTemplate.getInterceptors().add(new BasicAuthenticationInterceptor(USER_NAME,PASSWORD,StandardCharsets.UTF_8));
return restTemplate;

正如@MilacH指出的,在实现中有一个错误。如果返回statusCode > 400,则从拦截器抛出IOException,因为没有调用errorHandler。可以忽略异常,然后在处理程序方法中再次捕获异常。

package net.sprd.fulfillment.common;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import static java.nio.charset.StandardCharsets.UTF_8;

public class LoggingRequestInterceptor implements ClientHttpRequestInterceptor {

    final static Logger log = LoggerFactory.getLogger(LoggingRequestInterceptor.class);

    @SuppressWarnings("HardcodedLineSeparator")
    public static final char LINE_BREAK = '\n';

    @Override
    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
        try {
            traceRequest(request, body);
        } catch (Exception e) {
            log.warn("Exception in LoggingRequestInterceptor while tracing request", e);
        }

        ClientHttpResponse response = execution.execute(request, body);

        try {
            traceResponse(response);
        } catch (IOException e) {
            // ignore the exception here, as it will be handled by the error handler of the restTemplate
            log.warn("Exception in LoggingRequestInterceptor", e);
        }
        return response;
    }

    private void traceRequest(HttpRequest request, byte[] body) {
        log.info("===========================request begin================================================");
        log.info("URI         : {}", request.getURI());
        log.info("Method      : {}", request.getMethod());
        log.info("Headers     : {}", request.getHeaders());
        log.info("Request body: {}", new String(body, UTF_8));
        log.info("==========================request end================================================");
    }

    private void traceResponse(ClientHttpResponse response) throws IOException {
        StringBuilder inputStringBuilder = new StringBuilder();
        try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(response.getBody(), UTF_8))) {
            String line = bufferedReader.readLine();
            while (line != null) {
                inputStringBuilder.append(line);
                inputStringBuilder.append(LINE_BREAK);
                line = bufferedReader.readLine();
            }
        }

        log.info("============================response begin==========================================");
        log.info("Status code  : {}", response.getStatusCode());
        log.info("Status text  : {}", response.getStatusText());
        log.info("Headers      : {}", response.getHeaders());
        log.info("Response body: {}", inputStringBuilder);
        log.info("=======================response end=================================================");
    }

}

奇怪的是,这些解决方案都不能工作,因为RestTemplate似乎不会在某些客户机和服务器上返回500x错误的响应。在这种情况下,您还必须通过实现ResponseErrorHandler来记录这些日志,如下所示。这是一个代码草案,但你明白了:

你可以设置与错误处理程序相同的拦截器:

restTemplate.getInterceptors().add(interceptor);
restTemplate.setRequestFactory(new BufferingClientHttpRequestFactory(new SimpleClientHttpRequestFactory()));
restTemplate.setErrorHandler(interceptor);

拦截实现了两个接口:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashSet;
import java.util.Set;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpRequest;
import org.springframework.http.HttpStatus.Series;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.web.client.DefaultResponseErrorHandler;
import org.springframework.web.client.ResponseErrorHandler;

public class LoggingRequestInterceptor implements ClientHttpRequestInterceptor, ResponseErrorHandler {
    static final Logger log = LoggerFactory.getLogger(LoggingRequestInterceptor.class);
    static final DefaultResponseErrorHandler defaultResponseErrorHandler = new DefaultResponseErrorHandler();
    final Set<Series> loggableStatuses = new HashSet();

    public LoggingRequestInterceptor() {
    }

    public LoggingRequestInterceptor(Set<Series> loggableStatuses) {
        loggableStatuses.addAll(loggableStatuses);
    }

    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
        this.traceRequest(request, body);
        ClientHttpResponse response = execution.execute(request, body);
        if(response != null) {
            this.traceResponse(response);
        }

        return response;
    }

    private void traceRequest(HttpRequest request, byte[] body) throws IOException {
        log.debug("===========================request begin================================================");
        log.debug("URI         : {}", request.getURI());
        log.debug("Method      : {}", request.getMethod());
        log.debug("Headers     : {}", request.getHeaders());
        log.debug("Request body: {}", new String(body, "UTF-8"));
        log.debug("==========================request end================================================");
    }

    private void traceResponse(ClientHttpResponse response) throws IOException {
        if(this.loggableStatuses.isEmpty() || this.loggableStatuses.contains(response.getStatusCode().series())) {
            StringBuilder inputStringBuilder = new StringBuilder();

            try {
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(response.getBody(), "UTF-8"));

                for(String line = bufferedReader.readLine(); line != null; line = bufferedReader.readLine()) {
                    inputStringBuilder.append(line);
                    inputStringBuilder.append('\n');
                }
            } catch (Throwable var5) {
                log.error("cannot read response due to error", var5);
            }

            log.debug("============================response begin==========================================");
            log.debug("Status code  : {}", response.getStatusCode());
            log.debug("Status text  : {}", response.getStatusText());
            log.debug("Headers      : {}", response.getHeaders());
            log.debug("Response body: {}", inputStringBuilder.toString());
            log.debug("=======================response end=================================================");
        }

    }

    public boolean hasError(ClientHttpResponse response) throws IOException {
        return defaultResponseErrorHandler.hasError(response);
    }

    public void handleError(ClientHttpResponse response) throws IOException {
        this.traceResponse(response);
        defaultResponseErrorHandler.handleError(response);
    }
}

除了在另一个答案中描述的HttpClient日志之外,您还可以引入一个ClientHttpRequestInterceptor,它读取请求体和响应并记录它。如果其他东西也使用HttpClient,或者你想要一个自定义的日志格式,你可能需要这样做。注意:您需要给RestTemplate一个BufferingClientHttpRequestFactory,这样您就可以读取两次响应。