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