一、sentinel控制台的使用

1、sentinel控制台jar包地址：

Releases · alibaba/Sentinel · GitHub

账号密码都为sentinel

控制台访问地址：http://localhost:8080

2、sentinel的maven坐标

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
    <version>2021.1</version>
</dependency>

3、配置

spring:
  cloud:
    sentinel:
      transport:
        dashboard: localhost:8080

4、显示结果

访问http://localhost:8080进入控制台

二、sentinel整合feign的使用与步骤

1、yml文件进行开启

feign:
  sentinel:
    enabled: true

2、给FeignClient编写FallBackFactory并注册为bean

编写FallBackFactory（调用哪个Feign编写哪个）

@Component
public class ProductFeignFallbackFactory implements FallbackFactory<ProductFeign> {
    @Override
    public ProductFeign create(Throwable throwable) {
        return new ProductFeign() {
            @Override
            public R test() {
                System.out.println("熔断。。。。失败。。。");
                return R.failed("失败");
            }
        };
    }
}

注册为bean

public class FeignConfig {
    @Bean
    public ProductFeignFallbackFactory productFeignFallbackFactory(){
        return new ProductFeignFallbackFactory();
    }
}

3、将FallbackFactory配置到FeignClient（添加fallbackFactory=所配置的类）

@FeignClient(value = "shop-product",fallbackFactory = ProductFeignFallbackFactory.class)
public interface ProductFeign {
    @GetMapping("/shop/product/test")
    @ResponseBody
    public R test();
}