SpringCloud之Hystrix熔断降级（六）

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-hystrix</artifactId>
    <version>1.4.6.RELEASE</version>
</dependency>

server:
  port: 8001# 当前微服务的端口

mybatis:
  config-location: classpath:mybatis/mybatis-config.xml # mybatis配置文件所在路径
  type-aliases-package: com.common.springcloud.entity    # 所有饿entity实体类所在包
  mapper-locations:
    - classpath:mybatis/mapper/*.xml                # mapper映射文件

spring:
  application:
    name: springcloud-provider-dept-hystrix            # 对外暴露的微服务的名字(很重要)
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource      # 当前数据源操作类型
    driver-class-name: org.gjt.mm.mysql.Driver        # mysql驱动包
    url: jdbc:mysql://localhost:3306/db01?useUnicode=true&serverTimezone=GMT%2B8&characterEncoding=UTF-8&useSSL=false# 数据库名称
    username: root
    password: 123456druid:
    # 指明是否在从池中取出连接前进行检验,如果检验失败, 则从池中去除连接并尝试取出另一个，
    #注意: 设置为true后如果要生效,validationQuery参数必须设置为非空字符串
    test-on-borrow: false# 指明连接是否被空闲连接回收器(如果有)进行检验.如果检测失败,则连接将被从池中去除.
    #注意: 设置为true后如果要生效,validationQuery参数必须设置为非空字符串
    test-while-idle: true# 指明是否在归还到池中前进行检验，注意: 设置为true后如果要生效,
    #validationQuery参数必须设置为非空字符串
    test-on-return: false# SQL查询,用来验证从连接池取出的连接,在将连接返回给调用者之前.
    #如果指定,则查询必须是一个SQL SELECT并且必须返回至少一行记录
    validation-query: select 1
eureka:
  client:   #客户端注册进eureka服务列表内
    service-url:
      defaultZone: http://eureka1:7001/eureka/,http://eureka2:7002/eureka/,http://eureka3:7003/eureka/#去注册中心的地址
      #defaultZone:7001,7002,7003去注册中心的地址
  instance:
    instance-id: springcloud-dept-hystrix8001   #自定义hystrix相关的服务名称信息
    prefer-ip-address: true#访问路径可以显示ip地址

info:
  app.name: wj-springcloud
  company.name: www.wj.com
  build.artifactId: $project.artifactId$
  build.version: $project.version$                   

packagecom.yt.springcloud.controller;
importjava.util.List;
importorg.springframework.beans.factory.annotation.Autowired;
importorg.springframework.cloud.client.ServiceInstance;
importorg.springframework.cloud.client.discovery.DiscoveryClient;
importorg.springframework.web.bind.annotation.PathVariable;
importorg.springframework.web.bind.annotation.RequestBody;
importorg.springframework.web.bind.annotation.RequestMapping;
importorg.springframework.web.bind.annotation.RequestMethod;
importorg.springframework.web.bind.annotation.RestController;
importcom.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
importcom.yt.springcloud.entity.Dept;
importcom.yt.springcloud.service.impl.DeptService;

@RestController//整合了responceBody+Controller
public classDeptController {

    @Autowired
    private DeptService service = null;

    @RequestMapping(value = "/dept/get/{id}", method =RequestMethod.GET)
    //一旦调用服务方法失败并抛出了错误信息后，会自动调用@HystrixCommand标注好的fallbackMethod调用类中的指定方法
    @HystrixCommand(fallbackMethod = "processHystrix_Get")//发生异常的时候,会调用这个fallbackmethod方法,去处理
    public Dept get(@PathVariable("id") Long id){

        Dept dept = this.service.get(id);
        
        if (null ==dept) {
            throw new RuntimeException("该ID：" + id + "没有没有对应的信息");
        }
        
        returndept;
    }

    /*** 发生异常的时候,会调用这个方法来处理,还是返回一个dept对象,但是里面的信息是我们自定义的
*下面的链路赋值形式：new ObjectTest().setXX().setXX().....; 需要导入lombok依赖即可
     * @paramid
     * @return
     */
    public Dept processHystrix_Get(@PathVariable("id") Long id){
        return new Dept().setDeptno(id).setDname("该ID：" + id + "没有没有对应的信息,null--@HystrixCommand")
                .setDb_source("no this database in MySQL");
    }
}

packagecom.yt.springcloud;

importorg.springframework.boot.SpringApplication;
importorg.springframework.boot.autoconfigure.SpringBootApplication;
importorg.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
importorg.springframework.cloud.client.discovery.EnableDiscoveryClient;
importorg.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
@EnableEurekaClient //本服务启动后会自动注册进eureka服务中
@EnableDiscoveryClient //服务发现
@EnableCircuitBreaker//对hystrixR熔断机制的支持!!!
public classDeptProvider8001_Hystrix_App
{
    public static voidmain(String[] args)
    {
        SpringApplication.run(DeptProvider8001_Hystrix_App.class, args);
    }
}
 

packagecom.yt.springcloud.service;
importjava.util.List;
importorg.springframework.stereotype.Component;
importcom.yt.springcloud.entity.Dept;
importfeign.hystrix.FallbackFactory;
@Component
public class DeptClientServiceFallbackFactory implements FallbackFactory<DeptClientService>{
    @Override
    publicDeptClientService create(Throwable throwable)
    {
        return newDeptClientService() {
            @Override
            public Dept get(longid)
            {
                return new Dept().setDeptno(id).setDname("该ID：" + id + "没有没有对应的信息,Consumer客户端提供的降级信息,此刻服务Provider已经关闭")
                        .setDb_source("no this database in MySQL");
            }

            @Override
            public List<Dept>list()
            {
                return null;
            }

            @Override
            public booleanadd(Dept dept)
            {
                return false;
            }
        };
    }
}

importcom.common.springcloud.pojo.Dept;
importorg.springframework.cloud.openfeign.FeignClient;
importorg.springframework.web.bind.annotation.GetMapping;
importorg.springframework.web.bind.annotation.PathVariable;
importorg.springframework.web.bind.annotation.PostMapping;
importjava.util.List;
//@FeignClient(value = "SPRINGCLOUD-PROVIDER-DEPT")//针对于更细粒化的控制,针对哪一个微服务进行面向接口的feign的
@FeignClient(value = "SPRINGCLOUD-PROVIDER-DEPT", fallback = DeptClientServiceFallbackFactory.class)
public interfaceDeptClientService {
    @GetMapping("/dept/get/{id}")
    public Dept queryId(@PathVariable("id") Long id);

    @GetMapping("/dept/list")
    public List<Dept>queryAll();

    @PostMapping("/dept/list")
    public booleanaddDept(Dept dept);
}