maven笔记（三）

分模块构建工程

上一节中，利用maven构建了一个最基础的ssh项目，这一节将对该项目进行分模块构建工程。

通过聚合和继承构建

继承：创建一个parent工程将通用的pom配置抽取出来 聚合：聚合多个模块运行

需求

将ssh工程拆分为多个模块开发

dao + service + web

理解继承和聚合

通常继承和聚合同时使用

• 继承

继承是为了消除重复，如果将dao、service、web分开创建独立的工程则每个工程的pom.xml文件中的内容存在重复，比如：设置编译版本、锁定spring的版本的等，可以将这些重复的配置提取出来在父工程的pom.xml中定义。

• 聚合

项目开发通常是分组分模块开发，每个模块开发完成要运行整个工程需要将每个模块聚合在一起运行，比如：dao、service、web三个工程最终会打一个独立的war运行。

案例实现

maven-parent父模块

创建父工程

注意，父工程只是一个pom工程

定义pom.xml

在父工程的pom.xml中抽取一些重复的配置的，比如：锁定jar包的版本、设置编译版本等。

<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.yaolong.maven</groupId>  <artifactId>maven-parent</artifactId>  <version>0.0.1-SNAPSHOT</version>  <packaging>pom</packaging>  <name>parent project</name>    <!-- 属性 --><properties><spring.version>4.2.4.RELEASE</spring.version><hibernate.version>5.0.7.Final</hibernate.version><struts.version>2.3.24</struts.version></properties><dependencyManagement><dependencies><!-- 统一依赖构件版本 --><dependency><groupId>org.springframework</groupId><artifactId>spring-context</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-orm</artifactId><version>${spring.version}</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-test</artifactId><version>${spring.version}</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-web</artifactId><version>${spring.version}</version></dependency><dependency><groupId>org.hibernate</groupId><artifactId>hibernate-core</artifactId><version>${hibernate.version}</version></dependency><dependency><groupId>org.apache.struts</groupId><artifactId>struts2-core</artifactId><version>${struts.version}</version></dependency><dependency><groupId>org.apache.struts</groupId><artifactId>struts2-spring-plugin</artifactId><version>${struts.version}</version></dependency><dependency><groupId>org.apache.struts</groupId><artifactId>struts2-json-plugin</artifactId><version>${struts.version}</version></dependency></dependencies></dependencyManagement><build><finalName>maven-web</finalName><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><configuration><source>1.7</source><target>1.7</target><encoding>UTF-8</encoding></configuration></plugin></plugins></build>    </project>

将父工程发布至仓库

父工程创建完成执行maven-install将父工程发布到仓库方便子工程继承：

查看本地仓库，看到maven-parent已经被安装

maven-dao子模块

创建dao子模块

选择maven模块： 

这里指定模块名称，选择父工程，选择“跳过骨架选择”： 

定义pom.xml

dao模块的pom.xml文件中需要继承父模块，添加持久层需要的依赖坐标：

<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.yaolong.maven</groupId>    <artifactId>maven-parent</artifactId>    <version>0.0.1-SNAPSHOT</version>  </parent>    <artifactId>maven-dao</artifactId>  <packaging>jar</packaging>      <dependencies><dependency><groupId>org.hibernate</groupId><artifactId>hibernate-core</artifactId></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-aspects</artifactId></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-orm</artifactId></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-test</artifactId></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-web</artifactId></dependency><!-- 数据库驱动 --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.6</version><scope>runtime</scope></dependency><!-- c3p0 --><dependency><groupId>c3p0</groupId><artifactId>c3p0</artifactId><version>0.9.1.2</version></dependency><!-- 日志 --><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-log4j12</artifactId><version>1.7.2</version></dependency><!-- junit --><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.9</version><scope>test</scope></dependency></dependencies></project>

dao接口

将maven-web工程中的dao接口及domain类拷贝到src/main/java中：

配置文件

将applicationContext.xml拆分出一个applicationContext-dao.xml，此文件中只配置dao

applicationContext-dao.xml

<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx  http://www.springframework.org/schema/tx/spring-tx.xsd"><!-- dao --><bean id="newsDao" class="com.yaolong.maven.demo.dao.impl.NewsDaoImpl"><property name="sessionFactory" ref="sessionFactory"/></bean></beans>

applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx  http://www.springframework.org/schema/tx/spring-tx.xsd"><!-- 数据库连接池 --><bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"><property name="driverClass" value="com.mysql.jdbc.Driver" /><property name="jdbcUrl" value="jdbc:mysql://localhost:3306/hibernatedb" /><property name="user" value="root" /><property name="password" value="12345" /></bean><!-- 配置sessionFactory --><bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean"><!-- 依赖dataSource --><property name="dataSource" ref="dataSource"/><!-- 创建工厂需要加载hibernate映射文件 --><property name="configLocations" value="classpath:hibernate.cfg.xml"></property></bean></beans>

单元测试

package com.yaolong.maven.demo.dao.impl;import org.junit.Before;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import com.yaolong.maven.demo.dao.NewsDao;import com.yaolong.maven.demo.domain.News;@ContextConfiguration(locations = { "classpath:applicationContext.xml", "classpath:applicationContext-dao.xml"})@RunWith(SpringJUnit4ClassRunner.class)public class NewsDaoImplTest {@Autowiredprivate NewsDao newsDao;@Beforepublic void setUp() throws Exception {}@Testpublic void testFindNewsById() {News news = newsDao.findNewsById(1);System.out.println(news.getContent());}}

项目目录结构

maven-service子模块

创建service子模块

方法同maven-dao模块创建方法，模块名称为maven-service。

定义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>  <parent>    <groupId>com.yaolong.maven</groupId>    <artifactId>maven-parent</artifactId>    <version>0.0.1-SNAPSHOT</version>  </parent>  <artifactId>maven-service</artifactId>  <packaging>jar</packaging>    <dependencies>  <!-- junit --><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.9</version><scope>test</scope></dependency><!-- 依赖dao --><dependency><groupId>com.yaolong.maven</groupId><artifactId>maven-dao</artifactId><version>0.0.1-SNAPSHOT</version></dependency></dependencies></project>

• 创建applicationContext-service.xml，此文件中定义的service。

<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx  http://www.springframework.org/schema/tx/spring-tx.xsd"><!-- service --><bean id="newsService" class="com.yaolong.maven.demo.service.impl.NewsServiceImpl"><property name="newsDao" ref="newsDao"/></bean></beans>

NewsService.java

package com.yaolong.maven.demo.service;import com.yaolong.maven.demo.domain.News;public interface NewsService {public News findNewsById(Integer newsId);}

NewsServiceImpl.java

package com.yaolong.maven.demo.service.impl;import com.yaolong.maven.demo.dao.NewsDao;import com.yaolong.maven.demo.domain.News;import com.yaolong.maven.demo.service.NewsService;public class NewsServiceImpl implements NewsService {private NewsDao newsDao;public void setNewsDao(NewsDao newsDao) {this.newsDao = newsDao;}@Overridepublic News findNewsById(Integer newsId) {return this.newsDao.findNewsById(newsId);}}

单元测试

package com.yaolong.maven.demo.service.impl;import org.junit.Before;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import com.yaolong.maven.demo.domain.News;import com.yaolong.maven.demo.service.NewsService;@ContextConfiguration(locations = {"classpath:applicationContext.xml","classpath:applicationContext-service.xml","classpath:applicationContext-dao.xml" })@RunWith(SpringJUnit4ClassRunner.class)public class NewsServiceImplTest {@Autowiredprivate NewsService newsService;@Beforepublic void setUp() throws Exception {}@Testpublic void testFindCustomerById() {News news = newsService.findNewsById(1);System.out.println(news.getContent());}}

项目目录结构

maven-web子模块

创建web子模块

方法同maven-dao模块创建方法，模块名称为maven-web。

• action

package com.yaolong.maven.demo.action;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionSupport;import com.yaolong.maven.demo.domain.News;import com.yaolong.maven.demo.service.NewsService;public class NewsAction extends ActionSupport {private static final long serialVersionUID = 1L;private News news;public News getNews() {return news;}public void setNews(News news) {this.news = news;}    private NewsService newsService;    public NewsService getNewsService() {return newsService;}public void setNewsService(NewsService newsService) {this.newsService = newsService;}//根据主键获取新闻信息public String queryNews(){String id = ServletActionContext.getRequest().getParameter("id"); news = newsService.findNewsById(Integer.valueOf(id)); return SUCCESS;}        }

applicationContext-web.xml

<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx  http://www.springframework.org/schema/tx/spring-tx.xsd"> <!-- action --><bean id="newsAction" class="com.yaolong.maven.demo.action.NewsAction" scope="prototype"><property name="newsService" ref="newsService"/></bean></beans>

applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx  http://www.springframework.org/schema/tx/spring-tx.xsd"><import resource="classpath:applicationContext-web.xml"/><import resource="classpath:applicationContext-service.xml"/><import resource="classpath:applicationContext-dao.xml"/></beans>

模块聚合

修改父工程的pom.xml，添加：

<!-- 由于父工程要聚合子工程，配置modules -->   <modules>    <!-- 在modules中配置相对路径，相对父工程pom.xml的路径找到子工程的pom.xml -->   <module>maven-dao</module>   <module>maven-service</module>   <module>maven-web</module>   </modules>

注意：上边module中配置的路径，此路径是相对父工程的pom.xml文件找子工程的pom.xml文件的路径。

运行调试

方法1：

在maven-web工程的pom.xml中配置tomcat插件运行 运行maven-web工程它会从本地仓库下载依赖的jar包，所以当maven-web依赖的jar包内容修改了必须及时发布到本地仓库，比如：maven-web依赖的maven-service修改了，需要及时将maven-service发布到本地仓库。

方法2：

在父工程的pom.xml中配置tomcat插件运行，自动聚合并执行

推荐方法2，如果子工程都在本地，采用方法2则不需要子工程修改就立即发布到本地仓库，父工程会自动聚合并使用最新代码执行。

注意：如果子工程和父工程中都配置了tomcat插件，运行的端口和路径以子工程为准。