Spring Boot读取Nacos的配置文件

毕业版本依赖关系

链接：版本说明 · alibaba/spring-cloud-alibaba Wiki (github.com)

下表为按时间顺序发布的 Spring Cloud Alibaba 以及对应的适配 Spring Cloud 和 Spring Boot 版本关系（由于 Spring Cloud 版本命名有调整，所以对应的 Spring Cloud Alibaba 版本号也做了对应变化）

Spring Cloud Alibaba Version	Spring Cloud Version	Spring Boot Version
2021.0.1.0	Spring Cloud 2021.0.1	2.6.3
2.2.7.RELEASE	Spring Cloud Hoxton.SR12	2.3.12.RELEASE
2021.1	Spring Cloud 2020.0.1	2.4.2
2.2.6.RELEASE	Spring Cloud Hoxton.SR9	2.3.2.RELEASE
2.1.4.RELEASE	Spring Cloud Greenwich.SR6	2.1.13.RELEASE
2.2.1.RELEASE	Spring Cloud Hoxton.SR3	2.2.5.RELEASE
2.2.0.RELEASE	Spring Cloud Hoxton.RELEASE	2.2.X.RELEASE
2.1.2.RELEASE	Spring Cloud Greenwich	2.1.X.RELEASE
2.0.4.RELEASE(停止维护，建议升级)	Spring Cloud Finchley	2.0.X.RELEASE
1.5.1.RELEASE(停止维护，建议升级)	Spring Cloud Edgware	1.5.X.RELEASE

实现过程

创建父项目

创建一个Maven项目，用于管理依赖，pom.xml文件内容如下：

<?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>

    <groupId>org.example</groupId>
    <artifactId>NacosDemo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>nacos_config_test</module>
    </modules>
    <packaging>pom</packaging>

    <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>
        <spring-cloud.version>Hoxton.SR9</spring-cloud.version>
        <springboot.version>2.3.2.RELEASE</springboot.version>
        <springcloudalibaba.version>2.2.6.RELEASE</springcloudalibaba.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${springboot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${springcloudalibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

        </dependencies>
    </dependencyManagement>

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

</project>

创建子项目

在父项目下创建子项目，用于测试读取Nacos的配置文件

pom.xml

<?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>NacosDemo</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>nacos_config_test</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- 配置中心 -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>
    </dependencies>

</project>

创建配置文件

在resources下创建，bootstrap比application的优先级高

application.yml

server:
  port: 8080
  servlet:
    context-path: /

bootstrap.properties

#应用名称
spring.application.name=nacos_config_test
#Nacos的IP地址和端口号
spring.cloud.nacos.config.server-addr=121.41.111.106:8848
#Nacos配置文件所在组名
spring.cloud.nacos.config.group=DEFAULT_GROUP
#要读取的配置文件名称
spring.cloud.nacos.config.name=nacos_config.properties

新建Controller类

新建一个controller包，并在里面新建一个Controller类，@RefreshScope注解的作用为：当Nacos的配置文件内容改变后，也能读取修改后的配置，如果不使用这个注解则只能读取修改前的配置

package com.ledao.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.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author LeDao
 * @company
 * @create 2022-03-19 10:45
 */
@RefreshScope
@RestController
@RequestMapping("/nacos")
public class NacosConfigController {

    @Value("${ledao.name}")
    private String name;

    @Value("${ledao.age}")
    private String age;

    @GetMapping("/getUserInfo")
    public String getUserInfo(){
        return name + " : " + age;
    }
}

新建启动类

在上面新建的controller包外新建一个启动类，内容如下：

package com.ledao;

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

/**
 * @author LeDao
 * @company
 * @create 2022-03-19 10:38
 */
@SpringBootApplication
public class NacosConfigApplication {

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