一、开发步骤
1，创建一个父工程
点击Next
点击Finish后，它里面有一个pom.xml文件，这个文件可以将多个子模块中通用的jar所对应的坐标，
集中在父工程中配置，将来的子模块就可以不需要在pom.xml中配置，共用父模块jar。
2，创建一个子模块
点next,进入如下图：
点next,进入如下图：
再次查看父工程的pom.xml文件
并且内部所包含的结点，其实就是父工程的坐标
坐标=groupId+artifactId+version
组织名 项目名 版本
二、冲突问题的解决
在父工程中引入了struts-core,hibernate-core，就发现jar包是有冲突的
Javassist存在版本上冲突问题
背后的父工程的pom.xml文件中，添加的内容
2.依赖调解原则：
maven自动按照下边的原则调解：
(1) 第一声明者优先原则
在pom文件定义依赖，先声明的依赖为准。
测试：
如果将上边struts-spring-plugins和spring-context顺序颠倒，系统将导入spring-beans-4.2.4。
分析：
由于spring-context在前边以spring-context依赖的spring-beans-4.2.4为准，所以最终spring-beans-4.2.4添加到了工程中。
(2)路径近者优先原则
例如：A依赖 spirng-beans-4.2.4，A依赖B,B依赖 spirng-beans-3.0.5，则spring-beans-4.2.4优先被依赖在A中，
因为spring-beans-4.2.4相对spirng-beans-3.0.5被A依赖的路径最近。
测试：
在本工程中的pom中加入spirng-beans-4.2.4的依赖，根据路径近者优先原则，系统将导入spirng-beans-4.2.4
<dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>4.2.4.RELEASE</version> </dependency>
3.使用版本锁定实现冲突解决
首先父工程中pom.xml文件添加
注意：
在使用坐标时，对于同一个框架，引入多次时，它的版本信息就会多次出现，所以可以借用常量的思想，
将这些版本号提取出来，在需要用到的时候，直接写版本的常量名称就可以了。
最终在ssh_parent的pom.xml中引入的坐标
<!-- 为了确定每个框架的版本号 --> <!-- 锁定版本 --> <properties> <spring.version>4.2.4.RELEASE</spring.version> <struts2.version>2.3.24</struts2.version> <hibernate.version>5.0.7.Final</hibernate.version> <slf4j.version>1.6.6</slf4j.version> <log4j.version>1.2.12</log4j.version> <shiro.version>1.2.3</shiro.version> <cxf.version>3.0.1</cxf.version> <c3p0.version>0.9.1.2</c3p0.version> <mysql.version>5.1.6</mysql.version> </properties> <!-- 锁定版本，struts2-2.3.24、spring4.2.4、hibernate5.0.7 --> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <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>${hibernate.version}</version> </dependency> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-core</artifactId> <version>${struts2.version}</version> </dependency> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-spring-plugin</artifactId> <version>${struts2.version}</version> </dependency> </dependencies> </dependencyManagement> <dependencies> <dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>4.4</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.1.37</version> </dependency> <dependency> <groupId>commons-beanutils</groupId> <artifactId>commons-beanutils</artifactId> <version>1.9.1</version> </dependency> <!-- <dependency> <groupId>org.quartz-scheduler</groupId> <artifactId>quartz</artifactId> <version>2.2.1</version> </dependency> --> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.1</version> </dependency> <!-- jstl --> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <!-- shiro --> <!-- apache shiro dependencies --> <!-- <dependency> <groupId>org.apache.shiro</groupId> <artifactId>shiro-all</artifactId> <version>${shiro.version}</version> </dependency> --> <!-- spring --> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.6.8</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</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-orm</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-core</artifactId> <version>${spring.version}</version> </dependency> <!-- struts2 begin --> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-core</artifactId> <version>${struts2.version}</version> <exclusions> <exclusion> <artifactId>javassist</artifactId> <groupId>javassist</groupId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-spring-plugin</artifactId> <version>${struts2.version}</version> </dependency> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-json-plugin</artifactId> <version>${struts2.version}</version> </dependency> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-convention-plugin</artifactId> <version>${struts2.version}</version> </dependency> <!-- struts2 end --> <!-- hibernate begin --> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>${hibernate.version}</version> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-entitymanager</artifactId> <version>${hibernate.version}</version> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-validator</artifactId> <version>5.2.1.Final</version> </dependency> <!-- hibernate end --> <dependency> <groupId>c3p0</groupId> <artifactId>c3p0</artifactId> <version>${c3p0.version}</version> </dependency> <!-- <dependency> <groupId>org.apache.cxf</groupId> <artifactId>cxf-rt-frontend-jaxws</artifactId> <version>${cxf.version}</version> </dependency> <dependency> <groupId>org.apache.cxf</groupId> <artifactId>cxf-rt-transports-http</artifactId> <version>${cxf.version}</version> </dependency> --> <!-- log start --> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>${log4j.version}</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>${slf4j.version}</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>${slf4j.version}</version> </dependency> <!-- log end --> <!-- Javamail --> <!-- <dependency> <groupId>javax.mail</groupId> <artifactId>mail</artifactId> <version>1.4.4</version> </dependency> --> <dependency> <groupId>commons-lang</groupId> <artifactId>commons-lang</artifactId> <version>2.6</version> </dependency> <dependency> <groupId>org.codehaus.xfire</groupId> <artifactId>xfire-core</artifactId> <version>1.2.6</version> </dependency> <dependency> <groupId>dom4j</groupId> <artifactId>dom4j</artifactId> <version>1.6</version> </dependency> <!-- <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi</artifactId> <version>3.11</version> </dependency> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi-ooxml</artifactId> <version>3.11</version> </dependency> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi-ooxml-schemas</artifactId> <version>3.11</version> </dependency> --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> <!-- <dependency> <groupId>com.oracle</groupId> <artifactId>ojdbc14</artifactId> <version>10.2.0.4.0</version> </dependency> --> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> <scope>provided</scope> </dependency> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.0</version> <scope>provided</scope> </dependency> <dependency> <groupId>net.sf.ehcache</groupId> <artifactId>ehcache-core</artifactId> <version>2.6.6</version> </dependency> </dependencies>
依赖具有传递性，但不是无限传递的，传递的规则如下：
四、Web层的子模块创建
加入添加依赖service jar包后pom.xml会添加以下代码
