SpringCloud: 通过nacos配置中心来存储sentinel的限流规则

1.下载并启动本机sentinel dashboard

java -Dserver.port=9999 -Dcsp.sentinel.dashboard.server=localhost:9999 -Dproject.name=sentinel-dashboard -jar sentinel-dashboard-1.7.0.jar

2.在项目pom.xml中添加相关依赖

<?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">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>cn.edu.tju</groupId>
    <artifactId>spring-boot-sentinel-nacos</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Finchley.SR1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>



            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.0.0.RELEASE</version>
                <type>pom</type>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-openfeign -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.alibaba.cloud/spring-cloud-starter-alibaba-sentinel -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
            <version>2.0.4.RELEASE</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.alibaba.csp/sentinel-datasource-nacos -->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-datasource-nacos</artifactId>
            <version>1.8.0</version>
        </dependency>




        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

3.安装nacos并启动，在nacos中配置里增加相关的json 配置：
grade=1代表按QPS限流
count=2代表2QPS

[
    {
        "resource": "/testHello",
        "limitApp": "default",
        "grade": 1,
        "count": 2,
        "strategy": 0,
        "controlBehavior": 0,
        "clusterMode": false
    }
]

4.配置应用的配置文件application.yml

server:
  port: 8821
spring:
  application:
    name: sentinel-nacos
  cloud:
    sentinel:
      transport:
        #sentinel dashboard地址
        dashboard: localhost:9999
        port: 8719
      datasource:
        ds:
          nacos:
            #nacos地址
            server-addr: 139.198.xx.xx:8848
            #nacos中配置的限流规则的data id
            dataId: sentinel-service
            groupId: DEFAULT_GROUP
            data-type: json
            rule-type: flow
management:
  endpoints:
    web:
      exposure:
        exclude: '*'

5.创建controller,增加@SentinelResource注解，并编写流控使用的方法

package cn.edu.tju.controller;


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

@RestController
public class TestController {
    @RequestMapping("/hi")
    @SentinelResource(value="/testHello",blockHandler = "myBlockHandler")
    public String hi(){
        return "Hello,world";
    }

    public String myBlockHandler(BlockException ex){
        return "限流啦!!!";
    }

    @RequestMapping("/test")
    public String test(){
        return "test";
    }
}

6.编写启动类，并启动程序

package cn.edu.tju;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

7.在浏览器输入：http://localhost:8821/hi 并快速刷新，运行结果如下：