spring cloud alibaba之sentinel的使用（一）

模拟限流降级

https://github.com/alibaba/Sentinel/releases

下载的1.8.3版本

启动

 java -jar .sentinel-dashboard-1.8.3.jar

访问

http://localhost:8080/#/login

账号密码均为sentinel

sentinel-8401

    
    
        com.alibaba.cloud
        spring-cloud-starter-alibaba-nacos-discovery
    
    
    
        com.alibaba.csp
        sentinel-datasource-nacos
    
    
    
        com.alibaba.cloud
        spring-cloud-starter-alibaba-sentinel
    
    
    
        org.springframework.cloud
        spring-cloud-starter-openfeign
    
    
    
        org.springframework.boot
        spring-boot-starter-web
    
    
        org.springframework.boot
        spring-boot-starter-actuator
    
    
    
        org.springframework.boot
        spring-boot-devtools
        runtime
        true
    
    
        cn.hutool
        hutool-all
        4.6.3
    
    
        org.projectlombok
        lombok
        true
    
    
        org.springframework.boot
        spring-boot-starter-test
        test
    

server:
  port: 8401

spring:
  application:
    name: sentinel-service
  cloud:
    nacos:
      discovery:
        #Nacos服务注册中心地址
        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

management:
  endpoints:
    web:
      exposure:
        include: '*'

package com.xiong;

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

@EnableDiscoveryClient
@SpringBootApplication
public class Sentinel8401 {

    public static void main(String[] args) {
        SpringApplication.run(Sentinel8401.class,args);
    }
}

package com.xiong.controller;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {

    // 测试自定义异常
    @GetMapping("/testA")
    //testAName 断流配置用的名称、handleException返回的自定义异常
    @SentinelResource(value = "testAName",blockHandler = "handleException")
    public String testA()
    {
        return "------testA";
    }

    // 自定义异常
    public String handleException(BlockException exception)
    {
        return "自定义异常！！！！";
    }


    // 测试全局自定义异常
    @GetMapping("/rateLimit/customerBlockHandler")
    @SentinelResource(value = "customerBlockHandler", blockHandlerClass = CustomerBlockHandler.class, blockHandler = "handleException2")
    public String customerBlockHandler()
    {
        return "正常访问~~";
    }

}

package com.xiong.controller;

import com.alibaba.csp.sentinel.slots.block.BlockException;

public class CustomerBlockHandler
{
    public static String handleException2(BlockException exception){
        return "自定义全局异常";
    }
}

启动 nacos

启动 sentinel

启动 8401

先访问

http://localhost:8401/rateLimit/customerBlockHandler

访问成功之后，sentinel中出现此资源的列表

点击其中的按钮可以进行配置

配置完成后再次点击进行测试