SpringCloud 集成Sentinel的实战教程

java -jar jar包名

        <!--sentinel启动器-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>

server:
  port: 8002
spring:
  application:
    name: WXL-DEV-SERVICE-2
  cloud:
    sentinel:
      transport:
        dashboard: 127.0.0.1:8080

    @GetMapping("/world")
    @SentinelResource(value = "helloWorld",blockHandlerClass = TestController.class,blockHandler = "helloBlock")
    public String helloWorld() {
        return "Hello world";
    }
    public static String helloBlock(BlockException e){
        return "你已被流控";
    }

package com.dragonwu.exception;
import com.alibaba.csp.sentinel.adapter.spring.webmvc.callback.BlockExceptionHandler;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.csp.sentinel.slots.block.authority.AuthorityException;
import com.alibaba.csp.sentinel.slots.block.degrade.DegradeException;
import com.alibaba.csp.sentinel.slots.block.flow.FlowException;
import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowException;
import com.alibaba.csp.sentinel.slots.system.SystemBlockException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.HashMap;
import java.util.Map;
@Component
public class MyBlockExceptionHandler implements BlockExceptionHandler {
    @Override
    public void handle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, BlockException e) throws Exception {
        System.out.println("BlockExceptioonHandler ++++++++++++++++++++++++++"+e.getRule());
        Map<Integer,String> hashMap=new HashMap<>();
        if(e instanceof FlowException){
            hashMap.put(100,"接口限流了");
        }else if(e instanceof DegradeException){
            hashMap.put(101,"服务降级了");
        }else if(e instanceof ParamFlowException){
            hashMap.put(102,"热点参数限流了");
        }else if(e instanceof SystemBlockException){
            hashMap.put(103,"触发系统保护规则了");
        }else if(e instanceof AuthorityException){
            hashMap.put(104,"授权规则不通过");
        }
        //返回json数据
        httpServletResponse.setStatus(500);
        httpServletResponse.setCharacterEncoding("utf-8");
        httpServletResponse.setContentType(MediaType.APPLICATION_JSON_VALUE);
        new ObjectMapper().writeValue(httpServletResponse.getWriter(),hashMap);
    }
}
 

        <!--OpenFeign-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

feign:
  sentinel:
    enabled: true #开启openFeign对sentinel的整合

package com.wxl.feign;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
@FeignClient(name = "WXL-DEV-SERVICE-2", path = "/hello",fallback = ServiceFailFeign.class)
public interface Service1HelloInterface {
    @GetMapping("/world")
    String helloWorld();
}

package com.wxl.feign;
import org.springframework.stereotype.Component;
@Component
public class ServiceFailFeign implements Service1HelloInterface{
    public String helloWorld() {
        return "降级了！！！";
    }
}

    @GetMapping("/world")
    public String helloWorld() {
        int i=1/0;
        return "Hello world";
    }

        <!--sentinel持久化存储-->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-datasource-nacos</artifactId>
        </dependency>