解耦原因

下面代码使用@HystrixCommand(fallbackMethod = “getInfoFallback”)业务代码耦合度太高，不利于维护，所以需要整合Feign和Hystrix进行解耦

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/**
 * 获取信息
 *
 * @return
 * @throws InterruptedException
 */
@RequestMapping("/getInfo")
@HystrixCommand(fallbackMethod = "getInfoFallback")
public Map<String, Object> getInfo() throws InterruptedException {
    Thread.sleep(100);
    Map<String, Object> map = new HashMap<>(16);
    map.put("code", 200);
    map.put("info", "业务数据1004");
    return map;
}

/**
 * 请求超时就请求我
 *
 * @return
 */
public Map<String, Object> getInfoFallback() {
    Map<String, Object> map = new HashMap<>(16);
    map.put("code", 500);
    map.put("info", "系统出错，稍后重试");
    return map;
}

实现过程

修改Hystrix服务提供者项目

项目名为：microservice-student-provider-hystrix-1004和microservice-student-provider-hystrix-1005

在StudentService.java中添加新的接口：

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/**
 * 获取信息
 * @return
 */
Map<String,Object> getInfo();

在StudentServiceImpl.java中实现上面的接口

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@Override
public Map<String, Object> getInfo() {
    Map<String, Object> map = new HashMap<>(16);
    map.put("code", 200);
    map.put("info", "业务数据1004");
    return map;
}

在StudentProviderController.java中调用

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/**
 * 获取信息
 *
 * @return
 * @throws InterruptedException
 */
@RequestMapping("/getInfo")
public Map<String, Object> getInfo() throws InterruptedException {
    Thread.sleep(500);
    return studentService.getInfo();
}

修改公共项目

项目名为：microservice-common

在StudentClientService.java中添加getInfo接口方法，并修改@FeignClient注解为：@FeignClient(value = “MICROSERVICE-STUDENT”, fallbackFactory = StudentClientFallbackFactory.class)

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/**
 * 获取信息
 *
 * @return
 */
@RequestMapping("/student/getInfo")
Map<String, Object> getInfo();

新建StudentClientFallbackFactory.java，实现FallbackFactory<StudentClientService>接口

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package com.ledao.service;

import com.ledao.entity.Student;
import feign.hystrix.FallbackFactory;
import org.springframework.stereotype.Component;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author LeDao
 * @company
 * @create 2021-08-16 2:18
 */
@Component
public class StudentClientFallbackFactory implements FallbackFactory<StudentClientService> {

    @Override
    public StudentClientService create(Throwable throwable) {
        return new StudentClientService() {
            @Override
            public Student get(Integer id) {
                return null;
            }

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

            @Override
            public boolean save(Student student) {
                return false;
            }

            @Override
            public boolean delete(Integer id) {
                return false;
            }

            @Override
            public Map<String, Object> getInfo() {
                Map<String, Object> map = new HashMap<>(16);
                map.put("code", 500);
                map.put("info", "系统出错，稍后重试");
                return map;
            }
        };
    }
}

修改Feign消费者项目

项目名为：microservice-student-consumer-feign-80

在StudentConsumerFeignController.java中添加调用方法

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/**
 * 获取信息
 *
 * @return
 */
@RequestMapping("/getInfo")
public Map<String, Object> getInfo() {
    return studentClientService.getInfo();
}

application.yml加上hystrix支持

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feign:
  hystrix:
    enabled: true

配置超时时间

因为整合了Feign和Hystrix，原来服务提供者的Hystrix超时时间配置没用了，如何配置查看：Feign和Hystrix整合后配置超时时间

测试

启动以下项目：

microservice-eureka-server-2001

microservice-eureka-server-2002

microservice-eureka-server-2003

microservice-student-provider-hystrix-1004

microservice-student-provider-hystrix-1005

microservice-student-consumer-feign-80

如果超时的情况返回错误信息（500 系统出错，稍后重试），说明配置成功