feign 启用 hystrix

feign 默认没有启用 hystrix，添加配置，启用 hystrix

• feign.hystrix.enabled=true

application.yml 添加配置

feign:  hystrix:    enabled: true

启用 hystrix 后，访问服务
http://localhost:3001/item-service/35

默认1秒会快速失败，没有降级方法时，会显示白板页

可以添加配置，暂时减小降级超时时间，以便后续对降级进行测试

......feign:  hystrix:    enabled: true    hystrix:  command:    default:      execution:        isolation:          thread:            timeoutInMilliseconds: 500

feign + hystrix 降级

feign 远程接口中指定降级类

远程调用失败, 会执行降级类中的代码

ItemFeignService

...@FeignClient(name="item-service", fallback = ItemFeignServiceFB.class)public interface ItemFeignService {...

UserFeignService

...@FeignClient(name="user-service", fallback = UserFeignServiceFB.class)public interface UserFeignService {...

OrderFeignService

...@FeignClient(name="order-service",fallback = OrderFeignServiceFB.class)public interface OrderFeignService {...

降级类

降级类需要实现远程接口

ItemFeignServiceFB

package cn.tedu.sp09.service;import java.util.List;import org.springframework.stereotype.Component;import cn.tedu.sp01.pojo.Item;import cn.tedu.web.util.JsonResult;@Componentpublic class ItemFeignServiceFB implements ItemFeignService {  @Override  public JsonResult> getItems(String orderId) {    return JsonResult.err("无法获取订单商品列表");  }  @Override  public JsonResult decreaseNumber(List items) {    return JsonResult.err("无法修改商品库存");  }}

UserFeignServiceFB

package cn.tedu.sp09.service;import org.springframework.stereotype.Component;import cn.tedu.sp01.pojo.User;import cn.tedu.web.util.JsonResult;@Componentpublic class UserFeignServiceFB implements UserFeignService {  @Override  public JsonResult getUser(Integer userId) {    return JsonResult.err("无法获取用户信息");  }  @Override  public JsonResult addScore(Integer userId, Integer score) {    return JsonResult.err("无法增加用户积分");  }}

OrderFeignServiceFB

package cn.tedu.sp09.service;import org.springframework.stereotype.Component;import cn.tedu.sp01.pojo.Order;import cn.tedu.web.util.JsonResult;@Componentpublic class OrderFeignServiceFB implements OrderFeignService {  @Override  public JsonResult getOrder(String orderId) {    return JsonResult.err("无法获取商品订单");  }  @Override  public JsonResult addOrder() {    return JsonResult.err("无法保存订单");  }}

启动服务，访问测试

http://localhost:3001/item-service/35