spring cloud Hystrix 服务容错保护（一）

主要处理某一服务故障，无法访问时，不用长久等待，给与错误反馈

1.启动之前的三个项目  消费者 注册中心 服务提供者

2.终端服务提供者，再次访问报错

Whitelabel Error Page

This application has no explicit mapping for /error, so you are seeing this as a fallback.

Thu Dec 21 14:38:09 CST 2017

There was an unexpected error (type=Internal Server Error, status=500).

I/O error on GET request for "http://hmq-demo-server/ceshi": Connection refused: connect; nested exception is java.net.ConnectException: Connection refused: connect

3.加入服务容错保护，在消费者项目（hmq-ribbon-server）中加入 Hysrix 依赖

<dependency>
   <groupId>org.springframework.cloudgroupId>
   <artifactId>spring-cloud-starter-hystrixartifactId>
dependency>

4.主类（com.heimeiqiu.HmqDemoServerApplication）添加注解，开启断路器功能

@EnableCircuitBreaker

5.创建controller

package com.heimeiqiu.controller;

import com.heimeiqiu.service.HystirixService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

/**
 * Created by wxl on 2017/12/21.
 */
@RestController
public class HystirixController {
    @Autowired
    HystirixService hystirixService;

    @RequestMapping(value = "/hystirix-server",method= RequestMethod.GET)
    public String helloConsumer(){
        return hystirixService.hystirixService();
    }
}

6.创建service

package com.heimeiqiu.service;

import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

/**
 * Created by wxl on 2017/12/21.
 */
@Service
public class HystirixService {
    @Autowired
    RestTemplate restTemplate;

    @HystrixCommand(fallbackMethod = "hystrirxBack")
    public String hystirixService(){
        return restTemplate.getForEntity("http://hmq-demo-server/ceshi",String.class).getBody();
    }

    public String hystrirxBack(){
        return "坏事了";
    }
}

7.这时候再将服务提供者，当机

显示 坏事了