项目里使用了Feign进行远程调用，有时为了问题排查，需要开启请求和响应日志
下面简介一下如何开启Feign日志：
注：本文基于
- spring-boot-starter-parent 2.3.4.RELEASE
- spring-cloud-starter-openfeign 2.2.3.RELEASE
1、项目里定义FeignClient接口
package com.example.demo.feign;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
@FeignClient(name = "deom", url = "https://www.baidu.com")
public interface FeignDemo {
@GetMapping("/")
String test();
}
2、单个FeignClient接口开启日志
在 application.yml 里指定Feign接口日志级别为DEBUG，类型为FULL：
注：com.example.demo.feign.FeignDemo就是上面定义的FeignClient接口
logging:
level:
com.example.demo.feign.FeignDemo: debug
# 下面的配置，也可以写代码代替
# @Bean
# public Logger.Level level() { return Logger.Level.FULL; }
feign:
client:
config:
default:
loggerLevel: full
OK了，重启项目，调用 FeignDemo.test() 方法后，会输出如下日志：
2020-10-13 11:46:24.161 DEBUG 20824 --- [nio-8080-exec-4] com.example.demo.feign.FeignDemo : [FeignDemo#test] ---> GET https://www.baidu.com HTTP/1.1
2020-10-13 11:46:24.162 DEBUG 20824 --- [nio-8080-exec-4] com.example.demo.feign.FeignDemo : [FeignDemo#test] ---> END HTTP (0-byte body)
2020-10-13 11:46:24.255 DEBUG 20824 --- [nio-8080-exec-4] com.example.demo.feign.FeignDemo : [FeignDemo#test] <--- HTTP/1.1 200 OK (93ms)
2020-10-13 11:46:24.255 DEBUG 20824 --- [nio-8080-exec-4] com.example.demo.feign.FeignDemo : [FeignDemo#test] content-length: 2443
2020-10-13 11:46:24.255 DEBUG 20824 --- [nio-8080-exec-4] com.example.demo.feign.FeignDemo : [FeignDemo#test] content-type: text/html
2020-10-13 11:46:24.256 DEBUG 20824 --- [nio-8080-exec-4] com.example.demo.feign.FeignDemo : [FeignDemo#test] date: Tue, 13 Oct 2020 03:46:24 GMT
2020-10-13 11:46:24.256 DEBUG 20824 --- [nio-8080-exec-4] com.example.demo.feign.FeignDemo : [FeignDemo#test] server: bfe
2020-10-13 11:46:24.256 DEBUG 20824 --- [nio-8080-exec-4] com.example.demo.feign.FeignDemo : [FeignDemo#test]
2020-10-13 11:46:24.257 DEBUG 20824 --- [nio-8080-exec-4] com.example.demo.feign.FeignDemo : [FeignDemo#test]
百度一下，你就知道
3、所有FeignClient接口 开启日志
上面的方法，只能开启单个FeignClient接口，如果项目里有10个接口，那么要在yml里配置10项，而且以后添加新的FeignClient，还要记得去修改yml配置，太麻烦。
所以，下面是开启所有FeignClient接口日志的配置：
3.1、修改FeignConfiguration
自定义feign.Logger，如下：
package com.example.demo.cacheDemo;
import feign.slf4j.Slf4jLogger;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class FeignConfiguration {
@Bean
public feign.Logger logger() {
return new Slf4jLogger();
}
}
3.2、还是修改 application.yml 配置
logging:
level:
# 删除具体的FeignClient接口配置，只保留这一个就好了
feign.Logger: debug
# 也可以写代码代替
# @Bean
# public Logger.Level level() { return Logger.Level.FULL; }
feign:
client:
config:
default:
loggerLevel: full
3.3、OK了，此时项目里
不管新增多少个 FeignClient，都会输出日志。
4、重写FeignClient输出日志
根据上面输出的日志，可以看到是多条INFO日志，在并发时，很有可能会互相干扰，而且格式也无法调整。
我们知道，Feign默认情况下，是使用 feign.Client.Default 发起http请求；
我们可以重写Client，并注入Bean来替换掉 feign.Client.Default，从而实现日志记录，当然也可以做其它任意事情了，比如添加Header。下面是注入Bean的代码：
// 默认不注入，如果yml配置里有 logging.level.beinet.cn.demostudy.MyClient 才注入
@Bean
@ConditionalOnProperty("logging.level.beinet.cn.demostudy.MyClient")
MyClient getClient() throws NoSuchAlgorithmException, KeyManagementException {
// 忽略SSL校验
SSLContext ctx = SSLContext.getInstance("SSL");
X509TrustManager tm = new X509TrustManager() {
@Override
public void checkClientTrusted(X509Certificate[] chain, String authType) {
}
@Override
public void checkServerTrusted(X509Certificate[] chain, String authType) {
}
@Override
public X509Certificate[] getAcceptedIssuers() {
return null;
}
};
ctx.init(null, new TrustManager[]{tm}, null);
return new MyClient(ctx.getSocketFactory(), (hostname, sslSession) -> true);
}
下面是重写的Client完整代码：
package beinet.cn.demostudy;
import feign.Client;
import feign.Request;
import feign.Response;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.StreamUtils;
import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.SSLSocketFactory;
import java.io.*;
import java.util.Collection;
import java.util.Map;
@Slf4j
public class MyClient extends Client.Default {
public MyClient(SSLSocketFactory socketFactory, HostnameVerifier hostnameVerifier) {
super(socketFactory, hostnameVerifier);
}
@Override
public Response execute(Request request, Request.Options options) throws IOException {
StringBuilder sb = new StringBuilder("[log started]\r\n");
sb.append(request.httpMethod()).append(" ").append(request.url()).append("\r\n");
CombineHeaders(sb, request.headers()); // 请求Header
CombineBody(sb, request.body());
long costTime = -1;
Exception exception = null;
BufferingFeignClientResponse response = null;
long begin = System.currentTimeMillis();
try {
response = new BufferingFeignClientResponse(super.execute(request, options));
costTime = (System.currentTimeMillis() - begin);
} catch (Exception exp) {
costTime = (System.currentTimeMillis() - begin);
exception = exp;
throw exp;
} finally {
sb.append("\r\nResponse cost time(ms)： ").append(String.valueOf(costTime));
if (response != null)
sb.append(" status: ").append(response.status());
sb.append("\r\n");
if (response != null) {
CombineHeaders(sb, response.headers()); // 响应Header
sb.append("Body:\r\n").append(response.body()).append("\r\n");
}
if (exception != null) {
sb.append("Exception:\r\n ").append(exception.getMessage()).append("\r\n");
}
sb.append("\r\n[log ended]");
log.debug(sb.toString());
}
Response ret = response.getResponse().toBuilder()
.body(response.getBody(),
response.getResponse().body().length()).build();
response.close();
return ret;
}
private static void CombineHeaders(StringBuilder sb, Map> headers) {
if (headers != null && !headers.isEmpty()) {
sb.append("Headers:\r\n");
for (Map.Entry> ob : headers.entrySet()) {
for (String val : ob.getValue()) {
sb.append(" ").append(ob.getKey()).append(": ").append(val).append("\r\n");
}
}
}
}
private static void CombineBody(StringBuilder sb, byte[] body) {
if (body == null || body.length <= 0)
return;
sb.append("Body:\r\n").append(new String(body)).append("\r\n");
}
static final class BufferingFeignClientResponse implements Closeable {
private Response response;
private byte[] body;
private BufferingFeignClientResponse(Response response) {
this.response = response;
}
private Response getResponse() {
return this.response;
}
private int status() {
return this.response.status();
}
private Map> headers() {
return this.response.headers();
}
private String body() throws IOException {
StringBuilder sb = new StringBuilder();
try (InputStreamReader reader = new InputStreamReader(getBody())) {
char[] tmp = new char[1024];
int len;
while ((len = reader.read(tmp, 0, tmp.length)) != -1) {
sb.append(new String(tmp, 0, len));
}
}
return sb.toString();
}
private InputStream getBody() throws IOException {
if (this.body == null) {
this.body = StreamUtils.copyToByteArray(this.response.body().asInputStream());
}
return new ByteArrayInputStream(this.body);
}
@Override
public void close() {
this.response.close();
}
}
}
输出日志示例：
2020-10-15 16:48:26.081 DEBUG 15664 --- [ main] beinet.cn.demostudy.MyClient : [log started]
POST https://www.baidu.com?flg=3
Headers:
Content-Length: 14
Content-Type: text/plain;charset=UTF-8
Body:
abcde我是dddResponse cost time(ms)： 207 status: 200
Headers:
content-length: 2443
content-type: text/html
date: Thu, 15 Oct 2020 08:48:27 GMT
server: bfe
Body:
百度的html