Spring Cloud 2.x系列之Feign整合断路器Hystrix-CFANZ编程社区

上编说了Spring Cloud 2.x系列之RestTemplate+Ribbon整合断路器Hystrix，这篇来看看如何Feign整合断路器Hystrix，Feign整合断路器Hystrix也是相对比较简单的。Feign默认已经自带断路器Hystrix，所以不需要像RestTemplate+Ribbon整合断路器Hystrix那样需要在SpringBoot的启动类添加注解。但是Feign自带断路器并没有打开，需要做些额外的配置。

feign:
   hystrix:
     enabled: true

1、新建项目sc-eureka-client-consumer-feign-hystrix，对应的pom.xml文件如下

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0http://maven.apache.org/xsd/maven-4.0.0.xsd">

   <modelVersion>4.0.0</modelVersion>

   <groupId>spring-cloud</groupId>

   <artifactId>sc-eureka-client-consumer-feign</artifactId>

   <version>0.0.1-SNAPSHOT</version>

   <packaging>jar</packaging>

   <name>sc-eureka-client-consumer-feign</name>

   <url>http://maven.apache.org</url>



   <parent>

      <groupId>org.springframework.boot</groupId>

      <artifactId>spring-boot-starter-parent</artifactId>

      <version>2.0.4.RELEASE</version>

   </parent>

   <dependencyManagement>

      <dependencies>

        <dependency>

           <groupId>org.springframework.cloud</groupId>

           <artifactId>spring-cloud-dependencies</artifactId>

           <version>Finchley.RELEASE</version>

           <type>pom</type>

           <scope>import</scope>

        </dependency>

      </dependencies>

   </dependencyManagement>


   <properties>

      <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

      <maven.compiler.source>1.8</maven.compiler.source>

      <maven.compiler.target>1.8</maven.compiler.target>

   </properties>

   <dependencies>

      <!-- 说明是一个 eureka client-->

      <dependency>

        <groupId>org.springframework.cloud</groupId>

         <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>

      </dependency>



      <dependency>

        <groupId>org.springframework.boot</groupId>

        <artifactId>spring-boot-starter-web</artifactId>

      </dependency>



      <!-- <dependency>

             <groupId>org.springframework.cloud</groupId>

             <artifactId>spring-cloud-starter-feign</artifactId>

           <version>1.4.5.RELEASE</version>

         </dependency> -->

      <dependency>

        <groupId>org.springframework.cloud</groupId>

        <artifactId>spring-cloud-starter-openfeign</artifactId>

      </dependency>

   </dependencies>

</project>

备注：从继续关系可以看出spring-cloud-starter-openfeign已经集成断路器Hystrix

Spring Cloud 2.x系列之Feign整合断路器Hystrix_ribbon

2、新建springboot启动类

package sc.consumer;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

import org.springframework.cloud.openfeign.EnableFeignClients;



@SpringBootApplication

@EnableEurekaClient

@EnableFeignClients

publicclassConsumerFeignApplication {

   publicstaticvoid main(String[] args) {

      SpringApplication.run(ConsumerFeignApplication.class, args);

   }


}

3、新建配置文件bootstrap.yml和application.yml

bootstrap.yml

server:
  port: 5800

application.yml

spring:

  application:

    name: sc-eureka-client-consumer-feign-hystrix

eureka:

  client:
    registerWithEureka: true #是否将自己注册到Eureka服务中，默认为true

    fetchRegistry: true #是否从Eureka中获取注册信息，默认为true

    serviceUrl:

      defaultZone: http://localhost:5001/eureka/
feign:

  hystrix:
    enabled: true

说明：在application.yml配置文件添加了开启断路器Hystrix的配置项

Spring Cloud 2.x系列之Feign整合断路器Hystrix_data mining_02

4、新建服务消费者类UserService.java

package sc.consumer.service;


import java.util.Map;


import org.springframework.cloud.openfeign.FeignClient;

import org.springframework.web.bind.annotation.DeleteMapping;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.PostMapping;

import org.springframework.web.bind.annotation.PutMapping;

import org.springframework.web.bind.annotation.RequestBody;

import org.springframework.web.bind.annotation.RequestMapping;



import sc.consumer.model.User;

import sc.consumer.service.hystrix.UserServiceHystrix;


@FeignClient(value="sc-eureka-client-provider", fallback=UserServiceHystrix.class)

publicinterfaceUserService {



   @GetMapping("/user/getUser/{id}")

   Map<String, Object> getUser(@PathVariable(value ="id") Long id);



   @RequestMapping("/user/listUser")

   Map<String, Object> listUser();



   @PostMapping("/user/addUser")

   Map<String, Object> addUser(@RequestBody User user);


   @PutMapping("/user/updateUser")

   Map<String, Object> updateUser(@RequestBody User user);


   @DeleteMapping("/user/deleteUser/{id}")

   Map<String, Object> deleteUser(@PathVariable(value ="id") Long id);


}

可以看到在该类的FeignClient注解上添加了一个属性fallback

Spring Cloud 2.x系列之Feign整合断路器Hystrix_data mining_03

5、新建断路器处理类UserServiceHystrix.java

packagesc.consumer.service.hystrix;


import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;



import org.springframework.stereotype.Component;



import sc.consumer.model.User;

import sc.consumer.service.UserService;



@Component

public class UserServiceHystrix  implementsUserService{



   @Override

   public Map<String, Object> getUser(Long id) {

      Map<String,Object> result = new HashMap<String, Object>();

      result.put("code", "000000");

      result.put("msg", "success");

      User u = new User();

      u.setId(-1L);

      u.setUserName("failBackName");

      result.put("body", u);

      returnresult;

   }



   @Override

   public Map<String, Object> listUser() {

      Map<String,Object> result = new HashMap<String, Object>();

      result.put("code", "000000");

      result.put("msg", "success");

      List<User> list = newArrayList<User>();

      User u = new User();

      u.setId(-1L);

      u.setUserName("failBackName");

      list.add(u);

      result.put("body", list);

      returnresult;

   }



   @Override

   public Map<String, Object> addUser(User user) {

      Map<String,Object> result = new HashMap<String, Object>();

      result.put("code", "000000");

      result.put("msg", "success");

      result.put("body", 0);

      returnresult;

   }



   @Override

   public Map<String, Object> updateUser(User user) {

      Map<String,Object> result = new HashMap<String, Object>();

      result.put("code", "000000");

      result.put("msg", "success");

      result.put("body", 0);

      returnresult;

   }



   @Override

   public Map<String, Object> deleteUser(Long id) {

      Map<String,Object> result = new HashMap<String, Object>();

      result.put("code", "000000");

      result.put("msg", "success");

      result.put("body", 0);

      returnresult;

   }



}

该类实现了UserService接口，并实现了该接口的所有方法。

6、分别启动注册中心sc-eureka-server和服务提供者sc-eureka-client-provider

7、启动sc-eureka-client-consumer-feign-hystrix，并验证是否启动成功

方式一：查看日志看看对应的端口是启动

Spring Cloud 2.x系列之Feign整合断路器Hystrix_data mining_04

方式二：查看注册中心是否注册成功

Spring Cloud 2.x系列之Feign整合断路器Hystrix_ribbon_05

8、使用postman验证断路器是否启用

上篇从服务提供者是否正常启动验证断路器是否启动，今天看看从数据库是否启动来验证断路器是否启动

（1）MySQL服务正常启动时访问：

http://127.0.0.1:5800/feign/user/listUser

Spring Cloud 2.x系列之Feign整合断路器Hystrix_eureka_06

（2）MySQL服务关闭时访问

http://127.0.0.1:5800/feign/user/listUser

Spring Cloud 2.x系列之Feign整合断路器Hystrix_eureka_07

再看下后台日志：

Spring Cloud 2.x系列之Feign整合断路器Hystrix_openstack_08

其他接口可以自行按照以上方式进行验证，看看断路器是否启动

源码：

https://gitee.com/hjj520/spring-cloud-2.x/tree/master/sc-eureka-client-consumer-feign-hystrix