SpringCloud: polaris作为配置中心

一、安装并启动polaris
二、新建spring cloud项目并加入相应依赖

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.tencent</groupId>
    <artifactId>polaris2022</artifactId>
    <version>1.0-SNAPSHOT</version>



    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.10</version>
    </parent>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.tencent.cloud</groupId>
                <artifactId>spring-cloud-tencent-dependencies</artifactId>
                <version>1.7.0-2021.0.3</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>2021.0.3</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

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

        <dependency>
            <groupId>com.tencent.cloud</groupId>
            <artifactId>spring-cloud-starter-tencent-polaris-config</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-bootstrap</artifactId>
        </dependency>
    </dependencies>

</project>

三、在bootstrap.yml中配置polaris相关属性：

server:
  port: 48084
spring:
  application:
    name: ConfigExample
  cloud:
    polaris:
      address: grpc://127.0.0.1:8091
      namespace: default # 设置配置中心命名空间
      config:
        auto-refresh: true # auto refresh when config file changed
        groups:
        - name: ${spring.application.name} # group name
          files: [ "config/user.properties" ]

四，编写启动类：

package cn.edu.tju;

import org.springframework.beans.factory.annotation.Value;
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);
    }
}

五、编写controller，要加上@RefreshScop注解，让配置能自动刷新

package cn.edu.tju.controller;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RefreshScope
public class TestController {
    @Value("${name}")
    private String name;

    @GetMapping(value = "/name")
    public String name() {
        return name;
    }
}

六、去polaris控制台进行属性的配置：
创建配置分组 ConfigExample
创建配置文件 config/user.properties
修改user.properties的内容为：

name=amadeus2022

然后发布
七、启动spring cloud程序并访问：http://127.0.0.1:48084/name，
返回：​​​amadeusliu2022​​​ 去polaris控制台修改name的值为amadeusliu2023
再次访问：http://127.0.0.1:48084/name
返回: ​​amadeusliu2023​​