SpringCloud （五）、Hystrix断路器初体验-v1.0

一、在前文基础上咱们以MyClient和MyServer为例

二、MyClient引入依赖

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

三、在程序的启动类MyClientApplication加@EnableHystrix注解开启Hystrix

package com.myclient;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.hystrix.EnableHystrix;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

@EnableEurekaClient //启动EnableEureka客户端
@EnableDiscoveryClient
@SpringBootApplication
@EnableHystrix
public class MyClientApplication {
    public static void main(String[] args) {
        SpringApplication.run(MyClientApplication.class, args);
    }
    @Bean
    @LoadBalanced
    RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

四、改造DemoService类，在hiService方法上加上@HystrixCommand注解。该注解对该方法建立了熔断器的功能，并指定了fallbackMethod熔断方法，熔断方法直接返回了一个字符串，字符串为"hi,"+name+",sorry,error!"，代码以下：

package com.myclient.demo.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;

@Service
public class DemoService {
    @Autowired
    RestTemplate restTemplate;

    @HystrixCommand(fallbackMethod = "hiError")
    public String hiService(String name) {
        return restTemplate.getForObject("http://MYSERVER/myserver/demo/hello/"+name,String.class);
    }
    public String hiError(String name) {
        return "hi,"+name+",sorry,error!";
    }
}

五、启动：myclient 工程，当咱们访问http://127.0.0.1:8081/myclient/demo/hello/jackson浏览器显示：

六、关闭myserver的全部工程