Spring Cloud Feign 整合 Hystrix

在前面随笔Spring Cloud 之 Feign的feign工程基础上进行改造

1.pom.xml依赖不变

2.application.yml文件添加feign.hystrix.enabled=true开启Hystrix断路器,即:

spring:
  application:
    name: feign
server:
  port: 8766
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
feign:
  hystrix:
    enabled: true

3.新建Feign Hystrix 调用失败的回调类HystrixErrorFallBack

package com.dzpykj.hystrixService;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import com.dzpykj.feignInterface.HelloInterface;

@Component
public class HystrixErrorFallBack implements HelloInterface {

    @Value("${server.port}")
    String port;

    @Override
    public String hello(String name) {
        return "Sorry "+name+",when you are visting feign hystrix project,port:"+port+",you meet an error";
    }

}

4.在@FeignClient接口加入fallback回调类

package com.dzpykj.feignInterface;

import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

import com.dzpykj.hystrixService.HystrixErrorFallBack;

@FeignClient(value = "eurekaclient",fallback = HystrixErrorFallBack.class) //value为要负载均衡的spring.application.name
public interface HelloInterface {

    @RequestMapping("/hi") //负载均衡目标工程里面的哪个方法
    public String hello(@RequestParam(value="name") String name);
}

5.依次启动Eureka服务集群、Eureka单个客户端、Feign工程

5.1 按照Spring Cloud Eureka Server集群Demo级搭建的步骤启动Eureka服务peer1,peer2集群

5.2按照Spring Cloud Eureka服务Demo级搭建启动8763的Eureka客户端

5.3启动Feign工程

6.访问 http://localhost:8766/hello/chaixy

7.模拟eurekaclient服务异常:手动将eurekaclient服务关闭,再次访问 http://localhost:8766/hello/chaixy

可以看到,当eurekaclient服务关闭时,访问遇到异常,回调了异常回调类HystrixErrorFallBack