前提

• 一个可用的Eureka注册中心（文中以之前博客中双节点注册中心，不重要）
• 一个连接到这个注册中心的服务提供者

快速入门

项目搭建

搭建一个新maven项目，artifactid为Ribbon-consum-hystrix，依赖是在ribbon-customer项目上加入hystrix依赖，这里直接给出，pom.xml配置如下：

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0"

         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.cnblogs.hellxz</groupId>

    <artifactId>Ribbon-consum-hystrix</artifactId>

    <version>1.0-SNAPSHOT</version>

    <parent>

        <groupId>org.springframework.boot</groupId>

        <artifactId>spring-boot-starter-parent</artifactId>

        <version>1.5.9.RELEASE</version>

        <relativePath/>

    </parent>

    <dependencies>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-web</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.cloud</groupId>

            <artifactId>spring-cloud-starter-eureka</artifactId>

            <version>RELEASE</version>

        </dependency>

        <dependency>

            <groupId>org.springframework.cloud</groupId>

            <artifactId>spring-cloud-starter-ribbon</artifactId>

            <version>RELEASE</version>

        </dependency>

        <!--暴露各种指标-->

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-actuator</artifactId>

        </dependency>

        <!--hystrix熔断器-->

        <dependency>

            <groupId>org.springframework.cloud</groupId>

            <artifactId>spring-cloud-starter-hystrix</artifactId>

            <version>RELEASE</version>

        </dependency>

    </dependencies>

    <dependencyManagement>

        <dependencies>

            <dependency>

                <groupId>org.springframework.cloud</groupId>

                <artifactId>spring-cloud-dependencies</artifactId>

                <version>RELEASE</version>

                <scope>import</scope>

                <type>pom</type>

            </dependency>

        </dependencies>

    </dependencyManagement>

    <build>

        <plugins>

            <plugin>

                <groupId>org.springframework.boot</groupId>

                <artifactId>spring-boot-maven-plugin</artifactId>

            </plugin>

            <plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-compiler-plugin</artifactId>

                <configuration>

                    <source>1.8</source>

                    <target>1.8</target>

                </configuration>

            </plugin>

        </plugins>

    </build>

</project>

新建包com.cnblogs.hellxz,新建应用入口类RibbonApplication:

package com.cnblogs.hellxz;

import org.springframework.boot.SpringApplication;

import org.springframework.cloud.client.SpringCloudApplication;

import org.springframework.cloud.client.loadbalancer.LoadBalanced;

import org.springframework.context.annotation.Bean;

import org.springframework.web.client.RestTemplate;

/**

 * @Author : Hellxz

 * @Description: Hystrix熔断器使用HelloWorld

 * @Date : 2018/4/20 10:03

 */

@SpringCloudApplication

public class RibbonApplication {

    @Bean

    @LoadBalanced

    RestTemplate getRestTemplate(){

        return new RestTemplate();

    }

    public static void main(String[] args) {

        SpringApplication.run(RibbonApplication.class, args);

    }

}

resources目录下添加配置文件application.yml，其中defaultZone的url为实际注册中心defaultZone地址

server:

  port: 8088

spring:

  application:

    name: ribbon-hystrix

eureka:

  client:

    serviceUrl:

      defaultZone: http://peer1:1111/eureka/,http://peer2:1112/eureka/

在com.cnblogs.hellxz包下分别新建controller包和service包，controller包中新建RibbonController，代码如下：

package com.cnblogs.hellxz.controller;

import com.cnblogs.hellxz.servcie.RibbonService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.RestController;

/**

 * @Author : Hellxz

 * @Description: Ribbon消费者controller

 * @Date : 2018/4/20 10:07

 */

@RestController

public class RibbonController {

    @Autowired

    RibbonService service;

    @GetMapping("/hystrix/test")

    public String helloHystrix(){

        //调用服务层方法

        return service.helloService();

    }

}

service包下新建RibbonService，代码如下：

package com.cnblogs.hellxz.servcie;

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;

/**

 * @Author : Hellxz

 * @Description: Ribbon服务层

 * @Date : 2018/4/20 10:08

 */

@Service

public class RibbonService {

    @Autowired

    private RestTemplate restTemplate;

    @HystrixCommand(fallbackMethod = "hystrixFallback")

    public String helloService(){

        //调用服务提供者接口，正常则返回hello字符串

        return restTemplate.getForEntity("http://hello-service/hello", String.class).getBody();

    }

    /**

     * 调用服务失败处理方法

     * @return “error"

     */

    public String hystrixFallback(){

        return "error";

    }

}

项目最后的结构如图

测试

分别启动 注册中心--->服务提供者--->刚新建的项目

访问http://localhost:8088/hystrix/test

因为现在服务是正常的，返回了hello，如图



此时关闭服务提供者项目，再次访问，返回了error，如图