Feign之日志輸出

在我們?nèi)粘ｉ_發(fā)過程中铣耘，經(jīng)常會(huì)查看日志解決問題渊涝，那么Feign是不是也有日志輸出呢扼睬？
答案：是的。
在構(gòu)建@FeignClient注解修飾的服務(wù)客戶端時(shí)蹋辅，會(huì)為每一個(gè)客戶端都創(chuàng)建一個(gè)Feign.Logger實(shí)例钱贯，可以利用該日志對(duì)象的Debug模式來分析Feign的請(qǐng)求細(xì)節(jié)。

環(huán)境配置如下：

• SpringBoot：2.1.1.RELEASE
• SpringCloud：Greenwich.RC1
• Java：1.8
• Maven：3.5.2

Feign日志輸出說明

Feign的Level日志級(jí)別配置默認(rèn)是：NONE侦另，不要跟log日志混淆秩命。

日志級(jí)別枚舉類Logger.Level：

1. NONE：不輸出日志
2. BASIC：輸出請(qǐng)求方法尉共、URL、響應(yīng)狀態(tài)碼弃锐、執(zhí)行時(shí)間
3. HEADERS：基本信息以及請(qǐng)求和響應(yīng)頭
4. FULL：請(qǐng)求和響應(yīng)的heads袄友、body、metadata霹菊，建議使用這個(gè)級(jí)別

前期準(zhǔn)備

1. 一個(gè)服務(wù)注冊(cè)中心tairan-spring-cloud-eureka剧蚣，端口8761。參考SpringCloud組件：搭建Eureka服務(wù)注冊(cè)中心
2. 創(chuàng)建tairan-spring-cloud-feign-api核心工程浇辜，對(duì)外提供api接口券敌。
3. 創(chuàng)建服務(wù)提供者tairan-spring-cloud-feign-privder工程，提供/hello接口柳洋，端口為10001待诅，并注冊(cè)到服務(wù)中心。參考SpringCloud組件：將微服務(wù)提供者注冊(cè)到Eureka服務(wù)中心
4. 創(chuàng)建服務(wù)消費(fèi)者tairan-spring-cloud-feign-logger工程熊镣，提供/feign-hello接口卑雁，端口號(hào)為10003，并注冊(cè)到服務(wù)中心绪囱。參考SpringCloud組件：將微服務(wù)提供者注冊(cè)到Eureka服務(wù)中心

注意：2测蹲、3步驟tairan-spring-cloud-feign-api和tairan-spring-cloud-feign-privder項(xiàng)目借用SpringCloud組件：創(chuàng)建第一個(gè)Feign客戶端文章中創(chuàng)建的項(xiàng)目。

構(gòu)建項(xiàng)目

同樣的是采用idea開發(fā)工具創(chuàng)建一個(gè)SpringBoot項(xiàng)目鬼吵，在依賴選擇界面對(duì)應(yīng)的添加Web扣甲、Feign以及Eureka Discovery依賴，直接完成創(chuàng)建項(xiàng)目齿椅。
項(xiàng)目的pom.xml內(nèi)容如下所示：

......//省略部分
<artifactId>tairan-spring-cloud-feign-logger</artifactId>
<name>tairan-spring-cloud-feign-logger</name>
<description>Demo project for Spring Boot</description>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
    <skipTests>true</skipTests>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>com.tairan.chapter</groupId>
        <artifactId>tairan-spring-cloud-feign-api</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>
......//省略部分

tairan-spring-cloud-feign-logger配置

1. 添加FeignConfig配置類琉挖，修改Feign日志輸出級(jí)別，代碼如下：

package com.tairan.chapter.feign.log.config;

import feign.Logger;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * Feign配置
 * 該配置放到SpringBoot可以掃描到的路徑下
 */
@Configuration
public class FeignConfig {

    @Bean
    Logger.Level feignLevel() {
        return Logger.Level.FULL;
    }
}

注意：該配置放到SpringBoot可以掃描到的路徑下涣脚。

2. 因?yàn)槲伊?xí)慣yaml配置方式示辈，所以更改了application.properties文件為application.yml。

logging.level.<FeignClient>=debug開啟指定Feign客戶端的DEBUG模式日志遣蚀；
<FeignClient>為Feign客戶端定義接口的完整路徑

application.yml文件代碼如下所示：

spring:
  application:
    name: tairan-spring-cloud-feign-logger
server:
  port: 10003
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/
      # defaultZone: http://litairan:litairan@localhost:8761/eureka/
# 開啟Feign請(qǐng)求壓縮
feign:
  compression:
    request:
      enabled: true
      mime-types: text/xml,application/xml,application/json
      min-request-size: 2048
    response:
      enabled: true
  # Dalston SR1（待定）之后的版本默認(rèn)關(guān)閉hystrix對(duì)feign的支持矾麻，如果想要使用fallback功能這里必須啟用
  hystrix:
    enabled: true
logging:
  level:
    com.tairan.chapter.feign.api.HelloService: debug

3. 入口類修改@SpringBootApplication掃描路徑，可以掃描到Hystrix熔斷類芭梯，即tairan-spring-cloud-feign-api中的HelloServiceHystrix類险耀，在應(yīng)用主類中通過@EnableFeignClients注解開啟Feign功能，因?yàn)樾枰?cè)到服務(wù)中心玖喘，所以還需要@EnableDiscoveryClient注解胰耗，代碼如下所示：

package com.tairan.chapter.feign.log;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;

@SpringBootApplication(scanBasePackages = "com.tairan.chapter.feign")
@EnableDiscoveryClient
@EnableFeignClients("com.tairan.chapter.feign.api")
public class TairanSpringCloudFeignLoggerApplication {

    public static void main(String[] args) {
        SpringApplication.run(TairanSpringCloudFeignLoggerApplication.class, args);
    }

}

運(yùn)行測(cè)試

1. 啟動(dòng)服務(wù)注冊(cè)中心tairan-spring-cloud-eureka
2. 啟動(dòng)服務(wù)提供方tairan-spring-cloud-feign-provider
3. 啟動(dòng)服務(wù)消費(fèi)方tairan-spring-cloud-feign-logger
4. 訪問tairan-spring-cloud-feign-logger工程的/feign-hello接口，鏈接：http://localhost:10003/feign-hello芒涡，查看idea控制臺(tái)打印結(jié)果
5. 關(guān)閉服務(wù)提供方tairan-spring-cloud-feign-provider
6. 訪問tairan-spring-cloud-feign-logger工程的/feign-hello接口柴灯，鏈接：http://localhost:10003/feign-hello，查看idea控制臺(tái)打印結(jié)果

執(zhí)行4操作后费尽，訪問鏈接http://localhost:10003/feign-hello后赠群，idea控制臺(tái)打印結(jié)果如下所示：

2019-03-01 19:46:17.191 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] ---> GET http://tairan-spring-cloud-feign-provider/hello HTTP/1.1
2019-03-01 19:46:17.191 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] Accept-Encoding: gzip
2019-03-01 19:46:17.191 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] Accept-Encoding: deflate
2019-03-01 19:46:17.191 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] ---> END HTTP (0-byte body)
2019-03-01 19:46:17.197 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] <--- HTTP/1.1 200 (5ms)
2019-03-01 19:46:17.197 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] cache-control: no-cache, no-store, max-age=0, must-revalidate
2019-03-01 19:46:17.197 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] content-length: 40
2019-03-01 19:46:17.197 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] content-type: text/plain;charset=UTF-8
2019-03-01 19:46:17.197 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] date: Fri, 01 Mar 2019 11:46:17 GMT
2019-03-01 19:46:17.197 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] expires: 0
2019-03-01 19:46:17.197 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] pragma: no-cache
2019-03-01 19:46:17.197 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] x-content-type-options: nosniff
2019-03-01 19:46:17.197 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] x-frame-options: DENY
2019-03-01 19:46:17.197 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] x-xss-protection: 1; mode=block
2019-03-01 19:46:17.197 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] 
2019-03-01 19:46:17.198 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] tairan-spring-cloud-feign-provider:10001
2019-03-01 19:46:17.198 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] <--- END HTTP (40-byte body)

執(zhí)行5操作后，訪問鏈接http://localhost:10003/feign-hello后旱幼，idea控制臺(tái)打印結(jié)果如下所示：

2019-03-01 19:47:27.782 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] ---> GET http://tairan-spring-cloud-feign-provider/hello HTTP/1.1
2019-03-01 19:47:27.782 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] Accept-Encoding: gzip
2019-03-01 19:47:27.782 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] Accept-Encoding: deflate
2019-03-01 19:47:27.782 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] ---> END HTTP (0-byte body)
2019-03-01 19:47:27.791 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] <--- ERROR ConnectException: Connection refused (Connection refused) (8ms)
2019-03-01 19:47:27.792 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] java.net.ConnectException: Connection refused (Connection refused)
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
    ……

2019-03-01 19:47:27.792 DEBUG 6643 --- [ign-provider-10] c.tairan.chapter.feign.api.HelloService  : [HelloService#getMessage] <--- END ERROR

如上所示查描，Feign的日志輸出級(jí)別修改成功。

源碼位置

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