SpringBoot Nacos 安装、注解开发配置自动加载更新并监听

SpringBoot Nacos 安装及配置入门Demo

基于注解

安装

下载tar包

github https://github.com/alibaba/nacos/releases/tag/1.4.0 不过下载的有时候很慢

csdn https://download.csdn.net/download/HumorChen99/13344131 我发的，免费下

解压即可，在bin目录有startup.sh启动

#进入bin目录并以独立模式启动
./startup.sh -m standalone

在浏览器访问 http://ip:8848/nacos 账号密码默认都为nacos
添加一个测试配置 systemSwtich值设置为true

建立springboot项目

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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>springboot_nacos_demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot_nacos_demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>com.alibaba.boot</groupId>
            <artifactId>nacos-config-spring-boot-starter</artifactId>
            <version>0.2.7</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </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>

application.yml

nacos:
  config:
    server-addr: 192.168.108.129:8848
server:
  port: 80

controller代码

autoRefreshed参数为是否自动刷新，开启后一旦配置更新即可同步更新
NacosValue(value = “${systemSwitch:false}”,autoRefreshed = true)
systemSwitch:false 配置:默认值，也就是查不到的时候返回这个默认的

  package com.example.springboot_nacos_demo.controller;
  
  import com.alibaba.nacos.api.config.ConfigType;
  import com.alibaba.nacos.api.config.annotation.NacosValue;
  import com.alibaba.nacos.spring.context.annotation.config.NacosPropertySource;
  import org.springframework.web.bind.annotation.GetMapping;
  import org.springframework.web.bind.annotation.RequestMapping;
  import org.springframework.web.bind.annotation.RestController;
  
  @RestController
  @RequestMapping("/nacos")
  @NacosPropertySource(dataId = "example",autoRefreshed = true)
  public class NacosController {
      @NacosValue(value = "${systemSwitch:false}",autoRefreshed = true)
      private boolean systemSwitch;
  
      @GetMapping("/systemSwitch")
      public boolean getSystemSwitch(){
          return this.systemSwitch;
      }
  }

浏览器打开查看内容
监听配置更新事件 @NacosConfigListener(dataId = “example”)

type为配置类型，可以为properties yaml json等等
一旦配置变更，该方法将收到消息，做自定义处理

  @RestController
  @RequestMapping("/nacos")
  @NacosPropertySource(dataId = "example",autoRefreshed = true,type = ConfigType.JSON)
  public class NacosController {
      @NacosValue(value = "${systemSwitch:false}",autoRefreshed = true)
      private boolean systemSwitch;
  
      @NacosConfigListener(dataId = "example")
      public void onMessage(String msg){
          System.out.println(msg);
      }
      
      @GetMapping("/systemSwitch")
      public boolean getSystemSwitch(){
          return this.systemSwitch;
      }
  }