Maven 多模块项目（如微服务架构）中，父 POM（最外层） 和 子模块 POM（具体业务模块）的区别和联系

1. 父 POM 的核心职责

父 POM 是项目的 全局配置中心，负责统一管理依赖版本、插件版本和公共配置，确保所有子模块的一致性。

1.1 依赖管理 (dependencyManagement)

• 作用：集中定义依赖的版本和范围，子模块引用时无需重复指定版本。

• 示例：

  <!-- 父 POM -->
  <dependencyManagement><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><version>3.1.5</version></dependency></dependencies>
  </dependencyManagement>
  

1.2 插件管理 (pluginManagement)

• 作用：统一插件版本和默认配置，子模块按需启用。

• 示例：

  <!-- 父 POM -->
  <build><pluginManagement><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>3.11.0</version><configuration><source>17</source><target>17</target></configuration></plugin></plugins></pluginManagement>
  </build>
  

1.3 其他公共配置

• 定义全局属性（如 <properties> 中的 Java 版本）。
• 声明模块聚合（<modules>）。

   <modules><module>auth</module><module>gateway</module><module>modules</module><module>api</module><module>common</module>
  </modules>
  

---

2. 子模块 POM 的核心职责

子模块 POM 负责 具体模块的实现配置，继承父 POM 的依赖和插件模板，并按需覆盖或扩展。

2.1 依赖声明 (dependencies)

• 规则：

  • 如果依赖在父 POM 的 dependencyManagement 中定义，子模块只需声明 groupId 和 artifactId。
  • 如果依赖未在父 POM 中定义，需在子模块中完整声明（含版本）。

• 示例：

  <!-- 子模块 POM -->
  <dependencies><!-- 继承父 POM 的版本 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!-- 独立声明新依赖 --><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>2.0.33</version></dependency>
  </dependencies>
  

2.2 插件启用与覆盖 (plugins)

• 规则：

  • 如果插件在父 POM 的 pluginManagement 中定义，子模块只需声明插件坐标即可继承配置。
  • 子模块可覆盖父 POM 的插件配置（如修改参数、绑定生命周期）。

• 示例：

  <!-- 子模块 POM -->
  <build><plugins><!-- 继承父 POM 的编译插件配置 --><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId></plugin><!-- 覆盖父 POM 的配置 --><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-surefire-plugin</artifactId><configuration><skipTests>true</skipTests> <!-- 禁用测试 --></configuration></plugin></plugins>
  </build>
  

---

3. 核心对比表

配置项	父 POM	子模块 POM
依赖管理	<dependencyManagement> 定义版本	<dependencies> 声明具体依赖
插件管理	<pluginManagement> 定义版本和配置	<plugins> 启用插件或覆盖配置
版本控制	集中管理，避免冲突	继承父版本或独立声明
配置覆盖	不可覆盖	可覆盖父 POM 的配置（如插件参数）
强制性	可选（但推荐）	必须显式声明需要的依赖或插件

---

4. 使用场景示例

场景 1：统一管理 Spring Boot 依赖

• 父 POM：

  <dependencyManagement><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-dependencies</artifactId><version>3.1.5</version><type>pom</type><scope>import</scope></dependency></dependencies>
  </dependencyManagement>
  

• 子模块：

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

场景 2：覆盖插件配置

• 父 POM：

  <pluginManagement><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-surefire-plugin</artifactId><version>3.2.1</version><configuration><skipTests>false</skipTests></configuration></plugin></plugins>
  </pluginManagement>
  

• 子模块：

  <plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-surefire-plugin</artifactId><configuration><skipTests>true</skipTests> <!-- 覆盖父 POM 配置 --></configuration></plugin>
  </plugins>
  

---

5. 最佳实践

1. 父 POM 原则：
   • 仅在 dependencyManagement 和 pluginManagement 中定义版本，不直接使用 <dependencies> 或 <plugins>。
   • 通过 <properties> 统一管理版本号，避免硬编码。
2. 子模块原则：
   • 仅声明需要的依赖和插件，避免冗余配置。
   • 覆盖父 POM 配置时需明确标注（如注释说明）。
3. 版本一致性：
   • 公共依赖（如 Spring Boot、Lombok）应在父 POM 中统一管理。
   • 业务特定依赖（如某个工具类库）可在子模块中独立声明。

---

6:总结

• 父 POM 是 模板，负责定义“用什么版本”。
• 子模块 POM 是 实例，负责声明“具体用哪些”。
• 通过合理分工，既能保证一致性，又能满足模块个性化需求。

7:完整父子pom实例

1、父pom

<?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>com.wkl</groupId><artifactId></artifactId><version>3.6.5</version><name></name><url>http://www..vip</url><description>开发系统</description><properties><version>3.6.5</version><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding><java.version>1.8</java.version><spring-boot.version>2.7.18</spring-boot.version><spring-cloud.version>2021.0.9</spring-cloud.version><spring-cloud-alibaba.version>2021.0.6.1</spring-cloud-alibaba.version><spring-boot-admin.version>2.7.16</spring-boot-admin.version><tobato.version>1.27.2</tobato.version><kaptcha.version>2.3.3</kaptcha.version><pagehelper.boot.version>2.0.0</pagehelper.boot.version><druid.version>1.2.23</druid.version><namic-ds.version>4.3.1</namic-ds.version><commons.io.version>2.13.0</commons.io.version><velocity.version>2.3</velocity.version><fastjson.version>2.0.53</fastjson.version><jjwt.version>0.9.1</jjwt.version><minio.version>8.2.2</minio.version><poi.version>4.1.2</poi.version><springdoc.version>1.6.9</springdoc.version><transmittable-thread-local.version>2.14.4</transmittable-thread-local.version><org.mapstruct.version>1.6.3</org.mapstruct.version><hutool.version>5.8.25</hutool.version><lombok.version>1.18.30</lombok.version><!-- override dependency version --><tomcat.version>9.0.98</tomcat.version><logback.version>1.2.13</logback.version><spring-framework.version>5.3.39</spring-framework.version></properties><!-- 依赖声明 --><dependencyManagement><dependencies><!-- 覆盖SpringFramework的依赖配置--><dependency><groupId>org.springframework</groupId><artifactId>spring-framework-bom</artifactId><version>${spring-framework.version}</version><type>pom</type><scope>import</scope></dependency><!-- SpringCloud 微服务 --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-dependencies</artifactId><version>${spring-cloud.version}</version><type>pom</type><scope>import</scope></dependency><!-- SpringCloud Alibaba 微服务 --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-alibaba-dependencies</artifactId><version>${spring-cloud-alibaba.version}</version><type>pom</type><scope>import</scope></dependency><!-- SpringBoot 依赖配置 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-dependencies</artifactId><version>${spring-boot.version}</version><type>pom</type><scope>import</scope></dependency><!-- 覆盖logback的依赖配置--><dependency><groupId>ch.qos.logback</groupId><artifactId>logback-core</artifactId><version>${logback.version}</version></dependency><dependency><groupId>ch.qos.logback</groupId><artifactId>logback-classic</artifactId><version>${logback.version}</version></dependency><!-- 覆盖tomcat的依赖配置--><dependency><groupId>org.apache.tomcat.embed</groupId><artifactId>tomcat-embed-core</artifactId><version>${tomcat.version}</version></dependency><dependency><groupId>org.apache.tomcat.embed</groupId><artifactId>tomcat-embed-el</artifactId><version>${tomcat.version}</version></dependency><dependency><groupId>org.apache.tomcat.embed</groupId><artifactId>tomcat-embed-websocket</artifactId><version>${tomcat.version}</version></dependency><!-- FastDFS 分布式文件系统 --><dependency><groupId>com.github.tobato</groupId><artifactId>fastdfs-client</artifactId><version>${tobato.version}</version></dependency><!-- Springdoc webmvc 依赖配置 --><dependency><groupId>org.springdoc</groupId><artifactId>springdoc-openapi-ui</artifactId><version>${springdoc.version}</version></dependency><!-- 验证码 --><dependency><groupId>pro.fessional</groupId><artifactId>kaptcha</artifactId><version>${kaptcha.version}</version></dependency><!-- pagehelper 分页插件 --><dependency><groupId>com.github.pagehelper</groupId><artifactId>pagehelper-spring-boot-starter</artifactId><version>${pagehelper.boot.version}</version></dependency><!-- io常用工具类 --><dependency><groupId>commons-io</groupId><artifactId>commons-io</artifactId><version>${commons.io.version}</version></dependency><!-- excel工具 --><dependency><groupId>org.apache.poi</groupId><artifactId>poi-ooxml</artifactId><version>${poi.version}</version></dependency><!-- 代码生成使用模板 --><dependency><groupId>org.apache.velocity</groupId><artifactId>velocity-engine-core</artifactId><version>${velocity.version}</version></dependency><!-- JSON 解析器和生成器 --><dependency><groupId>com.alibaba.fastjson2</groupId><artifactId>fastjson2</artifactId><version>${fastjson.version}</version></dependency><!-- JWT --><dependency><groupId>io.jsonwebtoken</groupId><artifactId>jjwt</artifactId><version>${jjwt.version}</version></dependency><!-- 线程传递值 --><dependency><groupId>com.alibaba</groupId><artifactId>transmittable-thread-local</artifactId><version>${transmittable-thread-local.version}</version></dependency><!-- 核心模块 --><dependency><groupId>com.wkl</groupId><artifactId>-common-core</artifactId><version>${.version}</version></dependency><!-- 接口模块 --><dependency><groupId>com.wkl</groupId><artifactId>-common-swagger</artifactId><version>${.version}</version></dependency><!-- 安全模块 --><dependency><groupId>com.wkl</groupId><artifactId>-common-security</artifactId><version>${.version}</version></dependency><!-- 权限范围 --><dependency><groupId>com.wkl</groupId><artifactId>-common-datascope</artifactId><version>${.version}</version></dependency><!-- 多数据源 --><dependency><groupId>com.wkl</groupId><artifactId>-common-datasource</artifactId><version>${.version}</version></dependency><!-- 分布式事务 --><dependency><groupId>com.wkl</groupId><artifactId>-common-seata</artifactId><version>${.version}</version></dependency><!-- 日志记录 --><dependency><groupId>com.wkl</groupId><artifactId>-common-log</artifactId><version>${.version}</version></dependency><!-- 缓存服务 --><dependency><groupId>com.wkl</groupId><artifactId>-common-redis</artifactId><version>${.version}</version></dependency><!-- 系统接口 --><dependency><groupId>com.wkl</groupId><artifactId>-api-system</artifactId><version>${.version}</version></dependency><!-- map转换 --><dependency><groupId>org.mapstruct</groupId><artifactId>mapstruct</artifactId><version>${org.mapstruct.version}</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>${lombok.version}</version><scope>provided</scope></dependency><!--            <dependency>-->
<!--                <groupId>cn.hutool</groupId>-->
<!--                <artifactId>hutool-all</artifactId>-->
<!--                <version>${hutool.version}</version>-->
<!--            </dependency>--></dependencies></dependencyManagement><modules><module>auth</module><module>gateway</module><module>modules</module><module>api</module><module>common</module></modules><packaging>pom</packaging><dependencies><!-- bootstrap 启动器 --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-bootstrap</artifactId></dependency></dependencies><build><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><configuration><source>${java.version}</source><target>${java.version}</target><encoding>${project.build.sourceEncoding}</encoding></configuration></plugin></plugins><pluginManagement><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><version>${spring-boot.version}</version><executions><execution><goals><goal>repackage</goal></goals></execution></executions></plugin><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>3.11.0</version><configuration><annotationProcessorPaths><!-- Lombok 处理器 --><path><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.30</version></path><!-- MapStruct 处理器 --><path><groupId>org.mapstruct</groupId><artifactId>mapstruct-processor</artifactId><version>1.5.5.Final</version></path></annotationProcessorPaths></configuration></plugin></plugins></pluginManagement></build><repositories><repository><id>public</id><name>aliyun nexus</name><url>https://maven.aliyun.com/repository/public</url><releases><enabled>true</enabled></releases></repository></repositories><pluginRepositories><pluginRepository><id>public</id><name>aliyun nexus</name><url>https://maven.aliyun.com/repository/public</url><releases><enabled>true</enabled></releases><snapshots><enabled>false</enabled></snapshots></pluginRepository></pluginRepositories></project>

2、子pom

<?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>-modules</artifactId><groupId>com.wkl</groupId><version>3.6.5</version></parent><modelVersion>4.0.0</modelVersion><artifactId>business</artifactId><description>modules-bus业务模块</description><dependencies><!-- SpringCloud Alibaba Nacos --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!-- SpringCloud Alibaba Nacos Config --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId></dependency><!-- SpringCloud Alibaba Sentinel --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-sentinel</artifactId></dependency><!-- SpringBoot Actuator --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency><!-- Mysql Connector --><dependency><groupId>com.mysql</groupId><artifactId>mysql-connector-j</artifactId></dependency><!-- RuoYi Common DataSource --><dependency><groupId>com.wkl</groupId><artifactId>-common-datasource</artifactId></dependency><!-- RuoYi Common DataScope --><dependency><groupId>com.wkl</groupId><artifactId>-common-datascope</artifactId></dependency><!-- RuoYi Common Log --><dependency><groupId>com.wkl</groupId><artifactId>-common-log</artifactId></dependency><!-- RuoYi Common Swagger --><dependency><groupId>com.wkl</groupId><artifactId>-common-swagger</artifactId></dependency><dependency><groupId>co.elastic.clients</groupId><artifactId>elasticsearch-java</artifactId><version>8.15.5</version><exclusions><exclusion><artifactId>elasticsearch-rest-client</artifactId><groupId>org.elasticsearch.client</groupId></exclusion></exclusions></dependency><dependency><groupId>org.elasticsearch.client</groupId><artifactId>elasticsearch-rest-client</artifactId><version>8.15.5</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.17.0</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-core</artifactId><version>2.17.0</version></dependency><dependency><groupId>jakarta.json</groupId><artifactId>jakarta.json-api</artifactId><version>2.1.1</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency><!-- starter-test：junit + spring-test + mockito --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.mapstruct</groupId><artifactId>mapstruct</artifactId></dependency></dependencies><build><finalName>${project.artifactId}</finalName><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><executions><execution><goals><goal>repackage</goal></goals></execution></executions></plugin></plugins></build></project>