一、代碼示例

說明：此處使用的SpringBoot版本為2.1.13.RELEASE宁脊，SpringCloud版本為Greenwich.SR5断国。
此處不再貼server與client代碼
1、maven依賴

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>
    </dependencies>

2榆苞、application.yml

server:
  port: 9004
spring:
  application:
    name: ribbon-hystrix
eureka:
  instance:
    hostname: localhost
    prefer-ip-address: true
    instance-id: ribbon-hystrix-9004
  client:
    service-url:
      defaultZone: http://eureka7001:7001/eureka/,http://eureka7002:7002/eureka/,http://eureka7003:7003/eureka/
#info信息
info:
  app:
    name: ribbon-hystrix-9004
  company:
    name: www.xxx.com
  build:
    artifactId: ${project.artifactId}
    version: ${project.version}

3稳衬、啟動(dòng)類
啟動(dòng)類增加@EnableHystrix注解開啟Hystrix

package org.example;

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

@SpringBootApplication
@EnableHystrix
public class RibbonHystrix9004Application {

    public static void main(String[] args) {
        SpringApplication.run(RibbonHystrix9004Application.class,args);
    }

    @Bean
    @LoadBalanced
    RestTemplate restTemplate(){
        return new RestTemplate();
    }
}

4、其他java類
Controller類
Controller類增加@HystrixCommand注解坐漏，通過fallbackMethod指定熔斷對(duì)應(yīng)的方法薄疚，fallbackMethod對(duì)應(yīng)的值為Controller類下的方法

package org.example.controller;

import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
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 org.springframework.web.client.RestTemplate;

@RestController
public class RibbonHystrixController {

    @Autowired
    private RestTemplate restTemplate;

    @GetMapping("/hello/{name}")
    @HystrixCommand(fallbackMethod = "helloError")
    public String hello(@PathVariable String name){
        return restTemplate.getForObject("http://client/hello/"+name,String.class);
    }

    public String helloError(String name){
        return "helloError,"+name;
    }
}

2、測(cè)試驗(yàn)證

先后啟動(dòng)服務(wù)server赊琳、client與本服務(wù)街夭，訪問http://localhost:7001/

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