maven中pom.xml文件的继承关系

这是父类的pom.xml

<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>upload-common</groupId>  <artifactId>upload</artifactId>  <version>0.0.1-SNAPSHOT</version>  <packaging>pom</packaging>  <!-- 定义所有jar包的版本库 -->  <properties>  <fileupload-version>1.3.2</fileupload-version>  <mysql-version>5.1.6</mysql-version>  </properties>    <!-- 子项目直接加载 -->  <dependencies>  <dependency>  <groupId>commons-beanutils</groupId>  <artifactId>commons-beanutils</artifactId>  <version>1.9.0</version>  </dependency>  </dependencies></project>    

这是子类的pom.xml文件

      <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">   <!-- 只是定义所有的版本信息  提供给子项目使用   子项目可以选择性的加载-->  <dependencyManagement>  <dependencies>  <dependency>    <groupId>commons-fileupload</groupId>  <artifactId>commons-fileupload</artifactId>  <version>${fileupload-version}</version>  </dependency>  <dependency>    <groupId>mysql</groupId>  <artifactId>mysql-connector-Java</artifactId>  <version>${mysql-version}</version>  </dependency>  </dependencies>  </dependencyManagement></project>