1、配置文件

feign:sentinel:enabled: true

2、 编写一个工厂类

import com.cart.cartservice.client.ItemClient;
import com.cart.cartservice.entity.Item;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.openfeign.FallbackFactory;
import org.springframework.http.ResponseEntity;@Slf4j
public class ItemClientFallbackFactory implements FallbackFactory<ItemClient> {@Overridepublic ItemClient create(Throwable cause) {return new ItemClient() {@Overridepublic ResponseEntity<Item> queryById(Integer id) {log.error("查询对象失败", cause);//返回一个空对象return ResponseEntity.ok(new Item());}};}
}

需要实现FallbackFactory接口，其中ItemClient为客户端接口。 

3、声明这个类

import com.cart.cartservice.factory.ItemClientFallbackFactory;
import org.springframework.context.annotation.Bean;public class DefaultFeignConfig {@Beanpublic ItemClientFallbackFactory getItemClientFallbackFactory(){return new ItemClientFallbackFactory();}
}

4、ItemClient上添加openFeign注解的属性fallbackFactory = ItemClientFallbackFactory.class)

import com.cart.cartservice.entity.Item;
import com.cart.cartservice.factory.ItemClientFallbackFactory;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;@FeignClient(value = "item-service",fallbackFactory = ItemClientFallbackFactory.class)
public interface ItemClient {@GetMapping("item/{id}")ResponseEntity<Item> queryById(@PathVariable("id") Integer id);
}

这样就可以在Sentinel里面配置限流了。