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)。
我的日志记录器配置使用XML
<logger name="org.springframework.web.client.RestTemplate">
<level value="trace"/>
</logger>
然后你会得到如下内容:
DEBUG org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:92) : Reading [com.test.java.MyClass] as "application/json" using [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@604525f1]
通过HttpMessageConverterExtractor.java:92，你需要继续调试，在我的情况下，我得到了这个:
genericMessageConverter.write(requestBody, requestBodyType, requestContentType, httpRequest);
这:
outputMessage.getBody().flush();
outputMessage.getBody()包含http(post类型)发送的消息
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);
}
}
如果您正在使用任何ClientHttpRequestInterceptor，那么使用BufferingClientHttpRequestFactory配置RestTemplate的技巧将不起作用，如果您试图通过拦截器进行日志记录，则会发生这种情况。这是由于InterceptingHttpAccessor (RestTemplate的子类)的工作方式。
长话短说……只需要使用这个类来代替RestTemplate(注意它使用SLF4J日志API，根据需要编辑):
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Constructor;
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Map;
import javax.annotation.PostConstruct;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpRequest;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.web.client.RestTemplate;
/**
* A {@link RestTemplate} that logs every request and response.
*/
public class LoggingRestTemplate extends RestTemplate {
// Bleh, this class is not public
private static final String RESPONSE_WRAPPER_CLASS = "org.springframework.http.client.BufferingClientHttpResponseWrapper";
private Logger log = LoggerFactory.getLogger(this.getClass());
private boolean hideAuthorizationHeaders = true;
private Class<?> wrapperClass;
private Constructor<?> wrapperConstructor;
/**
* Configure the logger to log requests and responses to.
*
* @param log log destination, or null to disable
*/
public void setLogger(Logger log) {
this.log = log;
}
/**
* Configure the logger to log requests and responses to by name.
*
* @param name name of the log destination, or null to disable
*/
public void setLoggerName(String name) {
this.setLogger(name != null ? LoggerFactory.getLogger(name) : null);
}
/**
* Configure whether to hide the contents of {@code Authorization} headers.
*
* <p>
* Default true.
*
* @param hideAuthorizationHeaders true to hide, otherwise false
*/
public void setHideAuthorizationHeaders(boolean hideAuthorizationHeaders) {
this.hideAuthorizationHeaders = hideAuthorizationHeaders;
}
/**
* Log a request.
*/
protected void traceRequest(HttpRequest request, byte[] body) {
this.log.debug("xmit: {} {}\n{}{}", request.getMethod(), request.getURI(), this.toString(request.getHeaders()),
body != null && body.length > 0 ? "\n\n" + new String(body, StandardCharsets.UTF_8) : "");
}
/**
* Log a response.
*/
protected void traceResponse(ClientHttpResponse response) {
final ByteArrayOutputStream bodyBuf = new ByteArrayOutputStream();
HttpStatus statusCode = null;
try {
statusCode = response.getStatusCode();
} catch (IOException e) {
// ignore
}
String statusText = null;
try {
statusText = response.getStatusText();
} catch (IOException e) {
// ignore
}
try (final InputStream input = response.getBody()) {
byte[] b = new byte[1024];
int r;
while ((r = input.read(b)) != -1)
bodyBuf.write(b, 0, r);
} catch (IOException e) {
// ignore
}
this.log.debug("recv: {} {}\n{}{}", statusCode, statusText, this.toString(response.getHeaders()),
bodyBuf.size() > 0 ? "\n\n" + new String(bodyBuf.toByteArray(), StandardCharsets.UTF_8) : "");
}
@PostConstruct
private void addLoggingInterceptor() {
this.getInterceptors().add(new ClientHttpRequestInterceptor() {
@Override
public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution)
throws IOException {
// Log request
if (LoggingRestTemplate.this.log != null && LoggingRestTemplate.this.log.isDebugEnabled())
LoggingRestTemplate.this.traceRequest(request, body);
// Perform request
ClientHttpResponse response = execution.execute(request, body);
// Log response
if (LoggingRestTemplate.this.log != null && LoggingRestTemplate.this.log.isDebugEnabled()) {
final ClientHttpResponse bufferedResponse = LoggingRestTemplate.this.ensureBuffered(response);
if (bufferedResponse != null) {
LoggingRestTemplate.this.traceResponse(bufferedResponse);
response = bufferedResponse;
}
}
// Done
return response;
}
});
}
private ClientHttpResponse ensureBuffered(ClientHttpResponse response) {
try {
if (this.wrapperClass == null)
this.wrapperClass = Class.forName(RESPONSE_WRAPPER_CLASS, false, ClientHttpResponse.class.getClassLoader());
if (!this.wrapperClass.isInstance(response)) {
if (this.wrapperConstructor == null) {
this.wrapperConstructor = this.wrapperClass.getDeclaredConstructor(ClientHttpResponse.class);
this.wrapperConstructor.setAccessible(true);
}
response = (ClientHttpResponse)this.wrapperConstructor.newInstance(response);
}
return response;
} catch (Exception e) {
this.log.error("error creating {} instance: {}", RESPONSE_WRAPPER_CLASS, e);
return null;
}
}
private String toString(HttpHeaders headers) {
final StringBuilder headerBuf = new StringBuilder();
for (Map.Entry<String, List<String>> entry : headers.entrySet()) {
if (headerBuf.length() > 0)
headerBuf.append('\n');
final String name = entry.getKey();
for (String value : entry.getValue()) {
if (this.hideAuthorizationHeaders && name.equalsIgnoreCase(HttpHeaders.AUTHORIZATION))
value = "[omitted]";
headerBuf.append(name).append(": ").append(value);
}
}
return headerBuf.toString();
}
}
我同意花这么多功夫来做这件事很愚蠢。
这些答案都不能完全解决问题。Mjj1409实现了大部分功能，但方便地避免了记录响应的问题，因为这需要更多的工作。Paul Sabou提供了一个看似现实的解决方案，但没有提供足够的细节来实际实现(对我来说根本没用)。Sofiene得到了日志记录，但遇到了一个严重的问题:响应不再可读，因为输入流已经被消耗了!
我建议使用BufferingClientHttpResponseWrapper来包装响应对象，以允许多次读取响应体:
public class LoggingRequestInterceptor implements ClientHttpRequestInterceptor {
private static final Logger logger = LoggerFactory.getLogger(LoggingRequestInterceptor.class);
@Override
public ClientHttpResponse intercept(final HttpRequest request, final byte[] body,
final ClientHttpRequestExecution execution) throws IOException {
ClientHttpResponse response = execution.execute(request, body);
response = log(request, body, response);
return response;
}
private ClientHttpResponse log(final HttpRequest request, final byte[] body, final ClientHttpResponse response) {
final ClientHttpResponse responseCopy = new BufferingClientHttpResponseWrapper(response);
logger.debug("Method: ", request.getMethod().toString());
logger.debug("URI: ", , request.getURI().toString());
logger.debug("Request Body: " + new String(body));
logger.debug("Response body: " + IOUtils.toString(responseCopy.getBody()));
return responseCopy;
}
}
这将不会消耗InputStream，因为响应体被加载到内存中，可以多次读取。如果你的类路径上没有BufferingClientHttpResponseWrapper，你可以在这里找到简单的实现:
https://github.com/spring-projects/spring-android/blob/master/spring-android-rest-template/src/main/java/org/springframework/http/client/BufferingClientHttpResponseWrapper.java
设置RestTemplate:
LoggingRequestInterceptor loggingInterceptor = new LoggingRequestInterceptor();
restTemplate.getInterceptors().add(loggingInterceptor);
