关于java:Hystrix服务保护框架-服务降级Fallback

前言

后面咱们应用 @HystrixCommand 注解来做服务熔断降级。这种形式存在很大的弊病，代码冗余，并且是不论是否降级都当时开启了新线程，而应用fallback的形式则不调用feign办法前都是在之前的主线程中，只有超时了，才会开新线程来解决，这样性能上更好。

代码革新

Hystrix 应用类形式

//Hystrix 第二种形式，应用类形式
@RequestMapping("/getUserInfoByMemberHystrix2")
public BaseResponse getUserInfoByMemberHystrix2() {
    System.out.println("getUserInfoByMemberHystrix-->线程池名称：" + Thread.currentThread().getName());
 return memberServiceFeign.getUserInfo();
}

MemberServiceFallback

package com.baba.api.fallback;
import com.baba.api.entity.UserEntity;
import com.baba.api.feign.MemberServiceFeign;
import com.baba.wlb.base.BaseApiService;
import com.baba.wlb.base.BaseResponse;
import org.springframework.stereotype.Component;
/**
 * @Author wulongbo
 * @Date 2021/1/28 10:13
 * @Version 1.0
 */@Component
public class MemberServiceFallback extends BaseApiService implements MemberServiceFeign {
    @Override
 public UserEntity getMember(String name) {
        return null;
 }
    // 服务降级敌对提醒
 @Override
 public BaseResponse getUserInfo() {
        return setResultError("以类的形式写服务降级，服务器忙碌，请稍后重试！");
 }
}

MemberServiceFeign

@FeignClient(name = "app-member") 改为 @FeignClient(value = "app-member",fallback = MemberServiceFallback.class)

package com.baba.api.feign;
import com.baba.api.fallback.MemberServiceFallback;
import com.baba.api.service.IMemberService;
import org.springframework.cloud.openfeign.FeignClient;
/**
 * @Author wulongbo
 * @Date 2021/1/22 14:12
 * @Version 1.0
 *///@FeignClient(name = "app-member")
@FeignClient(value = "app-member",fallback = MemberServiceFallback.class)
public interface MemberServiceFeign extends IMemberService{
}

这样就实现了类的形式调用Fallback。