服务提供方:

导入依赖：

<!--openfeign-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <!--alibaba-sentinel-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>

yml配置sentine监控

   sentinel:
      transport:
        dashboard: localhost:8080 #配置Sentinel dashboard控制台服务地址
        port: 8719 #默认8719端口，假如被占用会自动从8719开始依次+1扫描,直至找到未被占用的端口

业务类：

@GetMapping("/pay/nacos/get/{orderNo}")
    @SentinelResource(value = "getPayByOrderNo",blockHandler = "handlerBlockHandler")
    public ResultData getPayByOrderNo(@PathVariable("orderNo") String orderNo)
    {
        //模拟从数据库查询出数据并赋值给DTO
        PayDTO payDTO = new PayDTO();

        payDTO.setId(1024);
        payDTO.setOrderNo(orderNo);
        payDTO.setAmount(BigDecimal.valueOf(9.9));
        payDTO.setPayNo("pay:"+ IdUtil.fastUUID());
        payDTO.setUserId(1);

        return ResultData.success("查询返回值："+payDTO);
    }

    public ResultData handlerBlockHandler(@PathVariable("orderNo") String orderNo, BlockException exception)
    {
        return ResultData.fail(ReturnCodeEnum.RC500.getCode(),"getPayByOrderNo服务不可用，" +
                "触发sentinel流控配置规则"+"\t"+"o(╥﹏╥)o");
    }

修改公共类（feignApi）

 导入依赖：

<!--openfeign-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <!--alibaba-sentinel-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>

新增接口:

package com.wen.cloud.apis;

import com.wen.cloud.component.PayFeignSentinelApiFallBack;
import com.wen.cloud.resp.ResultData;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;

@FeignClient(value = "nacos-payment-provider",fallback = PayFeignSentinelApiFallBack.class)
public interface PayFeignSentinelApi {
    @GetMapping("/pay/nacos/get/{orderNo}")
    public ResultData getPayByOrderNo(@PathVariable("orderNo") String orderNo);
}

服务降级类:

package com.wen.cloud.component;


import com.wen.cloud.apis.PayFeignSentinelApi;
import com.wen.cloud.resp.ResultData;
import com.wen.cloud.resp.ReturnCodeEnum;
import org.springframework.stereotype.Component;


@Component
public class PayFeignSentinelApiFallBack implements PayFeignSentinelApi
{
    @Override
    public ResultData getPayByOrderNo(String orderNo)
    {
        return ResultData.fail(ReturnCodeEnum.RC500.getCode(),"对方服务宕机或不可用，FallBack服务降级o(╥﹏╥)o");
    }
}

服务调用方:

 导入依赖：

<!--openfeign-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <!--alibaba-sentinel-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>

yml配置sentinel对feign的支持

# 激活Sentinel对Feign的支持
feign:
  sentinel:
    enabled: true

主业务类开启feign调用

业务类:

@Resource
    private PayFeignSentinelApi payFeignSentinelApi;

    @GetMapping(value = "/consumer/pay/nacos/get/{orderNo}")
    public ResultData getPayByOrderNo(@PathVariable("orderNo") String orderNo)
    {
        return payFeignSentinelApi.getPayByOrderNo(orderNo);
    }