Sentinel涉及的知识点比较多，我们这篇文章先看一下基础的，如何在Spring Cloud中引入Sentiel。

父工程

与前面章节介绍的父工程一样，这里之简单罗列一下依赖

<properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <junit.version>4.12</junit.version>
        <log4j.version>1.2.17</log4j.version>
        <lombok.version>1.16.18</lombok.version>
        <mysql.version>5.1.47</mysql.version>
        <druid.version>1.1.16</druid.version>
        <mybatis.spring.boot.version>1.3.0</mybatis.spring.boot.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.3.12.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.SR12</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
<!--                <version>2.1.0.RELEASE</version>-->
                <version>2.2.1.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>${druid.version}</version>
            </dependency>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${mysql.version}</version>
            </dependency>
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>${mybatis.spring.boot.version}</version>
            </dependency>
        </dependencies>
    </dependencyManagement>

添加服务提供者

添加依赖

<?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">
    <parent>
        <artifactId>Cloud2020</artifactId>
        <groupId>net.xiangcaowuyu</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloudalibaba-sentiel-service8401</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>


    <dependencies>
        <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>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.7.5</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>

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

        <dependency>
            <groupId>net.xiangcaowuyu</groupId>
            <artifactId>cloud-api-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>

</project>

修改配置文件

主要是配置Nacos服务器及Sentinel Dashboard的地址。

server:
  port: 8401
spring:
  application:
    name: cloudalibaba-sentinel-service
  cloud:
    nacos:
      discovery:
        server-addr: 192.168.120.180:1111
    sentinel:
      transport:
        dashboard: 192.168.120.180:9000
        # 默认8719端口，假如端口被占用，依次+1，直到找到未被占用端口
        port: 8719
management:
  endpoints:
    web:
      exposure:
        include: "*"

增加接口

@RestController
@Slf4j
public class FlowLimitController {

    @GetMapping("/testA")
    public String testA() {
        return "-----------testA";
    }

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

    @GetMapping("/testD")
    public String testD() {
        int age = 10 / 0;
        log.info(Thread.currentThread().getName() + "\ttestB");
        return "-----------testD";
    }

    @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) {
        return "--------------testHotkey";
    }
    public String deal_testHotkey(String p1, String p2, BlockException blockException) {
        return "--------------deal_testHotkey";
    }
}

测试

访问http://localhost:8401/testA,然后打开Sentinel Dashboard，可以看到我们当前定义的服务接口。
一定要访问依次我们的服务接口，否则在sentinel dashboard中无法看到