详解spring cloud使用Hystrix实现单个方法的fallback

<dependency>       <groupId>org.springframework.cloud</groupId>       <artifactId>spring-cloud-starter-hystrix</artifactId>     </dependency> 

package com.chhliu.springboot.restful.controller;  import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RestController;  import com.chhliu.springboot.restful.feignclient.UserFeignClient; import com.chhliu.springboot.restful.vo.User; import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;  @RestController public class RestTemplateControllerHystrixCommand {      @Autowired   private UserFeignClient client; // 使用Feign来消费Restful服务      @GetMapping("/get/{id}")   @HystrixCommand(fallbackMethod="findByIdFallback")// 使用HystrixCommand注解，在fallbackMethod属性中指定fallback的方法   public User findById(@PathVariable Long id) {     return client.findById(id);   }        // 覆写fallbackMethod中指定的方法，注意，此方法的返回值，参数必须与原方法一致   public User findByIdFallback(Long id){     User u = new User();     u.setName("zhangsan");     u.setUsername("chhliu");     u.setId(9L);     return u;   } } 

@EnableCircuitBreaker 

server.port:7904 # spring boot服务注册到Eureka Server上的应用名称 spring.application.name=springboot-rest-template-feign-hystrix eureka.instance.prefer-ip-address=true # Eureka Server注册服务的地址 eureka.client.service-url.defaultZone=http://chhliu:chhliu123456@localhost:8764/eureka springboot-h2.ribbon.NFLoadBalancerRuleClassName=com.netflix.loadbalancer.RetryRule hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds: 1 #为了测试Hystrix的fallback效果，此处将超时时间设置成1毫秒