Spring Cloud入门系列（二十二）- Spring Cloud Alibaba之服务熔断与限流Sentinel

新建模块 cloud-alibaba-sentinel-service8401

pom.xml内容如下

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>cloud201230</artifactId>
        <groupId>com.banana</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-alibaba-sentinel-service8401</artifactId>

    <dependencies>
        <!--   nacos config     -->
        <!--        <dependency>-->
        <!--            <groupId>com.alibaba.cloud</groupId>-->
        <!--            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>-->
        <!--        </dependency>-->
        <!--  SpringCloud alibaba nacos    -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!--后续做持久化用到-->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-datasource-nacos</artifactId>
        </dependency>
        <!--sentinel-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>
        <!--openfeign -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <!--web组件-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <!--引入自定义的api通用包-->
        <dependency>
            <groupId>com.banana</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

application.yml

server:
  port: 8401
spring:
  application:
    name: alibaba-sentinel-service
  cloud:
    nacos:
      discovery:
        #Nacos注册中心地址
        server-addr: localhost:8848
    sentinel:
      transport:
        #配置Sentinel dashboard地址
        dashboard: localhost:8080
        #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
        port: 8719
      datasource:
        dsl:
          nacos:
            server-addr: localhost:8848
            dataId: alibaba-sentinel-service
            groupId: DEFAULT_GROUP
            data_type: json
            rule-type: flow

management:
  endpoints:
    web:
      exposure:
        include: "*"

SentinelMain8401

package com.banana.springcloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

/**
 * @author layman
 * @date 2021/1/24
 */
@SpringBootApplication
@EnableDiscoveryClient
public class SentinelMain8401 {
    
    
    public static void main(String[] args) {
    
    
            SpringApplication.run(SentinelMain8401.class,args);
        }
}

CustomerBlockHandler

package com.banana.springcloud.myhandler;

import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.banana.springcloud.entity.CommonResult;

/**
 * @author layman
 * @description: TODO
 * @date 2021/10/24
 */
public class CustomerBlockHandler {
    
    
    public static CommonResult handlerException(BlockException exception) {
    
    
        return new CommonResult(4444, "按客戶自定义,global handlerException----1");
    }


    public static CommonResult handlerException2(BlockException exception) {
    
    
        return new CommonResult(4444, "按客戶自定义,global handlerException----2");
    }
}

FlowLimitController

package com.banana.springcloud.controller;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.concurrent.TimeUnit;

/**
 * @author layman
 * @date 2021/1/24
 */
@RestController
@Slf4j
public class FlowLimitController {
    
    
    @GetMapping("/testA")
    public String testA() {
    
    
        // 测试阈值类型：线程数
        /*try {
            TimeUnit.MILLISECONDS.sleep(800);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }*/
        return "------testA";
    }

    @GetMapping("/testB")
    public String testB() {
    
    
        log.info(Thread.currentThread().getName() + "\t" + "...testB");
        return "------testB";
    }

    @GetMapping("/testC")
    public String testC() {
    
    
        log.info("testC 异常比例");
        int age = 10 / 0;
        return "------testC";
    }

    @GetMapping("/testD")
    public String testD() {
    
    
        try {
    
    
            TimeUnit.SECONDS.sleep(1);
        } catch (InterruptedException e) {
    
    
            e.printStackTrace();
        }
        log.info("testD 测试RT");
        return "------testD";
    }

    @GetMapping("/testE")
    public String testE() {
    
    
        log.info("testE 测试异常数");
        int age = 10 / 0;
        return "------testE 测试异常数";
    }

    /**
     * 热点限流
     */
    @GetMapping("/testHotKey")
    @SentinelResource(value = "testHotKey", blockHandler = "deal_testHotKey")
    public String testHotKey(@RequestParam(value = "p1", required = false) String p1,
                             @RequestParam(value = "p2", required = false) String p2) {
    
    
        int age = 10 / 0;
        return "------testHotKey";
    }

    public String deal_testHotKey(String p1, String p2, BlockException exception) {
    
    
        //sentinel系统默认的提示：Blocked by Sentinel (flow limiting)
        return "------deal_testHotKey,o(╥﹏╥)o";
    }

}