Maven的聚合和依赖

一个经典的Maven工程结构大致可以划分为：

1、聚合模块

2、用于配置公共属性、依赖管理和插件管理的超级模块

3、其他功能模块

工程结构：

聚合模块
|
-------- 超级模块
|	    |
| 	    pom.xml
|
-------- 功能模块
|	    |
| 	    pom.xml
|
pom.xml

聚合模块pom：

<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.michael</groupId>
  <artifactId>account-aggregator</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>pom</packaging>

  <name>account-aggregator</name>
  <modules>

  <module>account-parent</module>
  <module>account-email</module>
  <module>account-persist</module>
  <module>account-view</module>
  </modules>
</project>

超级模块pom:

<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  
  <groupId>com.michael</groupId>
  <artifactId>account-parent</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>pom</packaging>
  <name>account-parent</name>
  
  <properties>
  	<account-global-version>0.0.2-SNAPSHOT</account-global-version>
  	<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
  
</project>

功能模块A pom：

<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  
  <parent>
    <groupId>com.michael</groupId>
    <artifactId>account-parent</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <!-- 
    元素relativePath表示父模块POM的相对路径。
    当项目构建时，Maven会首先根据该元素制定的相对路径检查父POM，
    如果找不到，再从本地库查找。
    该元素的默认值使../pom.xml
    -->
    <relativePath>../account-parent/pom.xml</relativePath>
  </parent>
  
  <groupId>com.michael</groupId>
  <artifactId>account-email</artifactId>
  <version>${account-global-version}</version>
  <name>account-email</name>
  <packaging>jar</packaging>
  
</project>

功能模块B pom:

<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>com.michael</groupId>
    <artifactId>account-parent</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <relativePath>../account-parent/pom.xml</relativePath>
  </parent>
  <groupId>com.michael</groupId>
  <artifactId>account-view</artifactId>
  <version>${account-global-version}</version>
  <packaging>war</packaging>
  
  <build>
    <finalName>account-view</finalName>
  </build>
</project>