maven 之分模块构建web项目 及 聚合与继承特性

说明：一下总结文档 工具为：Eclipse ， 框架：spring + springMVC + Mybatis + maven

为什么要分模块开发？ 很简单提高代码的清晰和重用。

先给大家看一下分模块项目目录架构（如图）

介绍：如上图有一个父项目(user-parent)聚合很多子项目 (user-dao, user-service, user-web）。每个项目，不管是父子，都含有一个pom.xml文件。而且要注意的是，每个模块都标出了打包类型。

注意：父项目是pom,也只能是pom。子项目有jar，或者war。根据它包含的内容具体考虑。

了解到这儿，接下来开始搭建项目：

1. 新建maven项目详解（如图）

 

 2.重复以上的步骤一次新建 userService

3. 先建userWeb步骤（如图：）

 

4. 先建user-parent步骤（如图：）

 

注意：一定要注意，user-parent 选择packaging 为 pom.

5. 编写userDao层代码：

   因为新建项目自动生成类可以根据需求修改或删除。

  dao层是一些mybatis的配置，映射 和 log4j配置，以及vo类，在这里就不详细介绍，主要介绍 pom.xml内容：

  项目结构（如图）

　

pom.xml代码：

<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>

<parent>
 <groupId>com.wh.user</groupId>
  <artifactId>user-parent</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <relativePath>../user-parent/pom.xml</relativePath>
</parent>


<groupId>com.wh.user</groupId>
  <artifactId>userDao</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>userDao</name>
  <url>http://maven.apache.org</url>

  <properties>
    <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>
    
      <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.3.0</version>
    </dependency>
    
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.24</version>
    </dependency>
    
        <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency> 
  </dependencies>
</project>

6. 编写userService层代码：

   新建项目自动生成类可以根据需求修改或删除。

  dao层是一些spring的配置，不详细介绍，主要介绍 pom.xml内容：

  项目结构（如图）

 

pom.xml代码：

<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.wh.user</groupId>
  <artifactId>user-service</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>userService</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
   <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-core</artifactId>
          <version>4.1.7.RELEASE</version>
      </dependency>
      <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-beans</artifactId>
          <version>4.1.7.RELEASE</version>
      </dependency>
      <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-tx</artifactId>
         <version>4.1.7.RELEASE</version>
        </dependency>
      <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-context</artifactId>
          <version>4.1.7.RELEASE</version>
      </dependency>
      <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-context-support</artifactId>
          <version>4.1.7.RELEASE</version>
      </dependency>
      <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
        <version>4.1.7.RELEASE</version>
    </dependency>
      
      <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>4.1.7.RELEASE</version>
    </dependency>
    
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aop</artifactId>
        <version>4.1.7.RELEASE</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aspects</artifactId>
        <version>4.1.7.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>4.1.7.RELEASE</version>
    </dependency>
  
      <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.2.3</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>com.wh.user</groupId>
        <artifactId>userDao</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </dependency>
  </dependencies>
</project>

重点： 红色标记代码 为依赖userDao.

7. 编写userWeb层代码：

   注意项目结构，以及web.xml内容（可能项目自动生成内容与实际想要不符需要修改）；

   个人建议，在新建一个web项目，将web.xml，和 META-INF文件假手动粘贴即可。

  项目结构（如图）

web.xml配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance  http://www.springmodules.org/schema/cache/springmodules-cache.xsd http://www.springmodules.org/schema/cache/springmodules-ehcache.xsd" 
          xmlns="http://java.sun.com/xml/ns/javaee" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>MyBatisPro05</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  
    <!-- Spring配置文件 -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
    <!-- 编码过滤器 -->
    <filter>
        <filter-name>encodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <async-supported>true</async-supported>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <!-- Spring监听器 -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    
    <!-- 添加对springmvc的支持 -->
    <servlet>
        <servlet-name>springMVC</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-mvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
        <async-supported>true</async-supported>
    </servlet>
    <servlet-mapping>
        <servlet-name>springMVC</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>
</web-app>

pom.xml如下：

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.wh.user</groupId>
  <artifactId>userWeb</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>
  <dependencies>
         <!-- 添加Servlet支持 -->
      <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
    </dependency>
    
    <dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>javax.servlet.jsp-api</artifactId>
        <version>2.3.1</version>
    </dependency>
    
    <!-- 添加jtl支持 -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>
    
  
      <!-- 添加Spring支持 -->
    <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-core</artifactId>
          <version>4.1.7.RELEASE</version>
      </dependency>
      <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-beans</artifactId>
          <version>4.1.7.RELEASE</version>
      </dependency>
      <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-tx</artifactId>
         <version>4.1.7.RELEASE</version>
        </dependency>
      <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-context</artifactId>
          <version>4.1.7.RELEASE</version>
      </dependency>
      <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-context-support</artifactId>
          <version>4.1.7.RELEASE</version>
      </dependency>
      
      <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
        <version>4.1.7.RELEASE</version>
    </dependency>
    
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>4.1.7.RELEASE</version>
    </dependency>
  
  
      <dependency>
          <groupId>com.wh.user</groupId>
          <artifactId>userService</artifactId>
          <version>0.0.1-SNAPSHOT</version>
      </dependency>
  
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
  <build>
    <finalName>userWeb</finalName>
    
    <resources>  
    <resource>  
        <directory>src/main/java</directory>  
        <includes>  
            <include>**/*.xml</include>  
        </includes>  
        <filtering>true</filtering>  
    </resource>  
</resources> 
    
  </build>
</project>

 重点：红色标记代码 为依赖userService

8. 编写user-parent层代码：

   注意项目结构，该项目除了有一个 pom.xml 其他的都不需要；

   项目结构（如图）

pom.xml代码如：

<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.wh.user</groupId>
  <artifactId>user-parent</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>pom</packaging>
  
 <modules>
      <module>../user-dao</module>
      <module>../user-service</module>
  </modules>
  
  <properties>
      <spring.version>4.1.7.RELEASE</spring.version>
      <junit.version>4.12</junit.version>
      <log4j.version>1.2.17</log4j.version>
  </properties>
  
  <dependencyManagement>
      <dependencies>
          <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.3.0</version>
        </dependency>
        
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.24</version>
        </dependency>
        
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>${log4j.version}</version>
        </dependency>
      
        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>${junit.version}</version>
          <scope>test</scope>
        </dependency>
        
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-core</artifactId>
          <version>${spring.version}</version>
      </dependency>
      <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-beans</artifactId>
          <version>${spring.version}</version>
      </dependency>
      <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-tx</artifactId>
         <version>${spring.version}</version>
        </dependency>
      <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-context</artifactId>
          <version>${spring.version}</version>
      </dependency>
      <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-context-support</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>
    
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aop</artifactId>
        <version>${spring.version}</version>
    </dependency>
    
    
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aspects</artifactId>
        <version>${spring.version}</version>
    </dependency>

    
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>4.1.7.RELEASE</version>
    </dependency>
  
      <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.2.3</version>
    </dependency>
    
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
    </dependency>
    
    <dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>javax.servlet.jsp-api</artifactId>
        <version>2.3.1</version>
    </dependency>
    
    <!-- 添加jtl支持 -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>
      </dependencies>
  </dependencyManagement>
  
</project>

重点：该pom.xml中， 蓝色标记：为聚合实现。 红色标记：为依赖版本定义；

模块构建web项目已经完成。

 继承特性：

为每个需要继承的 pom.xml 文件中加入<parent>标签即可。

 <parent>
 <groupId>com.wh.user</groupId>
  <artifactId>user-parent</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <relativePath>../user-parent/pom.xml</relativePath>

</parent>

 谢谢，总结纯属自己巩固流程，如有看不懂抱歉。