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)。
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。
在Apache HttpClient的帮助下登录Logback:
在类路径中需要Apache HttpClient:
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.10</version>
</dependency>
配置您的RestTemplate以使用HttpClient:
restTemplate.setRequestFactory(new HttpComponentsClientHttpRequestFactory());
要记录请求和响应，请添加到Logback配置文件:
<logger name="org.apache.http.wire" level="DEBUG"/>
或者记录更多:
<logger name="org.apache.http" level="DEBUG"/>
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=================================================");
}
}
