Maven依赖管理之parent与dependencyManagement深入分析

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.4.RELEASE</version>
</parent>

<!--只是对版本号进行管理，不会实际引入jar-->
<dependencyManagement>  
      <dependencies>  
            <dependency>
            		<!--jar包身份限定-->
                <groupId>org.springframework</groupId>
                <artifactId>spring-core</artifactId>  
                <!--版本号的声明-->
                <version>3.2.7</version>
            </dependency>  
    </dependencies>  
</dependencyManagement>  
<!--会实际下载声明的依赖jar包-->
<dependencies>  
       <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-core</artifactId>
                <!--不声明version 标签，则会继承dependencyManagement-->
       </dependency>  
</dependencies>

<!--parent-module父模块pom.xml-->
<properties>
    <!--统一管理jar包版本。集中在父模块properties标签中定义所有依赖的版本号。-->
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <org.eclipse.persistence.jpa.version>1.2.6</org.eclipse.persistence.jpa.version>
    <javaee-api.version>1.8</javaee-api.version>
</properties>
<dependencyManagement>  
    <!--定义公共依赖的版本号-->
    <dependencies> 
        <dependency>  
            <groupId>org.eclipse.persistence</groupId>  
            <artifactId>org.eclipse.persistence.jpa</artifactId>  
            <version>${org.eclipse.persistence.jpa.version}</version>  
            <scope>provided</scope>  
        </dependency>  
        <dependency>  
            <groupId>javax</groupId>  
            <artifactId>javaee-api</artifactId>  
            <version>${javaee-api.version}</version>  
        </dependency>  
    </dependencies>  
</dependencyManagement> 

<!--son-module子模块pom.xml-->
<!--继承父类-->  
<parent>
    <!--声明父类的身份信息-->
    <artifactId>parent-module</artifactId>
    <groupId>com.ppd</groupId>  
    <version>0.0.1-SNAPSHOT</version> 
    <!--声明父类的pom文件路径-->
    <relativePath>../parent-module/pom.xml</relativePath>
</parent>  
<modelVersion>4.0.0</modelVersion>  
<artifactId>son-module</artifactId>  
<packaging>ejb</packaging>  
<!--依赖关系-->  
<dependencies>  
    <dependency>  
        <groupId>javax</groupId>  
        <artifactId>javaee-api</artifactId>
        <!--未声明则继承父类version、scope-->
    </dependency>  
    <dependency>  
        <groupId>com.fasterxml.jackson.core</groupId>  
        <artifactId>jackson-annotations</artifactId>
        <!--声明则不继承父类version-->
        <version>1.8<version/>
        <!--继承父类scope-->
    </dependency>  
    <dependency>  
        <groupId>org.eclipse.persistence</groupId>  
        <artifactId>org.eclipse.persistence.jpa</artifactId>
        <!--未声明则继承父类version-->
        <scope>provided</scope>
    </dependency>  
</dependencies>

   <properties>
        <spring-version>4.3.7.RELEASE</spring-version>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-WEB</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring-version}</version>
        </dependency>
    </dependencies>