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)。
我终于找到了正确的方法。
大部分的解决方案来自
我如何配置Spring和SLF4J以获得日志记录?
看来有两件事需要做:
在log4j中添加以下行。属性:log4j.logger.httpclient.wire=DEBUG
确保spring不会忽略您的日志配置
第二个问题主要发生在使用slf4j的spring环境中(就像我的例子一样)。
因此,当使用slf4j时,请确保发生以下两件事:
There is no commons-logging library in your classpath : this can be done by adding the exclusion descriptors in your pom :
<exclusions><exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
The log4j.properties file is stored somewhere in the classpath where spring can find/see it. If you have problems with this, a last resort solution would be to put the log4j.properties file in the default package (not a good practice but just to see that things work as you expect)
用一些代码扩展@hstoerr answer:
创建LoggingRequestInterceptor来记录请求响应
public class LoggingRequestInterceptor implements ClientHttpRequestInterceptor {
private static final Logger log = LoggerFactory.getLogger(LoggingRequestInterceptor.class);
@Override
public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
ClientHttpResponse response = execution.execute(request, body);
log(request,body,response);
return response;
}
private void log(HttpRequest request, byte[] body, ClientHttpResponse response) throws IOException {
//do logging
}
}
设置创建RestTemplate
RestTemplate rt = new RestTemplate();
//set interceptors/requestFactory
ClientHttpRequestInterceptor ri = new LoggingRequestInterceptor();
List<ClientHttpRequestInterceptor> ris = new ArrayList<ClientHttpRequestInterceptor>();
ris.add(ri);
rt.setInterceptors(ris);
rt.setRequestFactory(new BufferingClientHttpRequestFactory(new SimpleClientHttpRequestFactory());
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。