maven学习（5）-Maven 聚合与继承特性
接着上面的项目，
继承和聚合为了统一管理；
聚合：
有些项目中有很多小模块，可以合并到一起，将多个子项目可以统一管理，可以对user-dao，user-service进行统一管理（maven clean等。。），编译，测试等；使用modules把多个模块写进去；
继承：
可以看到user-service和user-web这两个项目里面pom添加的jar包，spring的jar包很多一样，版本一样，
很多重复了；
版本号都一样了，可以搞一个父类，然后将这些版本信息统一管理；不然项目多的话，版本多起来也是挺复杂；
新建user-parent项目，对user-dao和user-service统一管理（聚合），同时对user-dao和user-service、user-web中的jar进行统一版本管理：
新建user-parent，只要有一个pom.xml就行了，所以new maven project，create a simple project（跳过一些骨架选项）；
group id： com.cy.user
artifact id：user-parent
version：0.0.1-SNAPSHOT
packaging：pom
user-parent项目下，只有一个pom.xml就行了：
将user-dao、user-service、user-web中的依赖包都复制到user-parent中来，统一定义版本；user-dao、service、web项目pom.xml就不需要写版本号了；
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>com.cy.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>5.1.22</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>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.2.3</version> </dependency> <!-- 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jstl支持 --> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> </dependencies> </dependencyManagement> </project>
user-dao/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.cy.user</groupId> <artifactId>user-parent</artifactId> <version>0.0.1-SNAPSHOT</version> <relativePath>../user-parent/pom.xml</relativePath> </parent> <artifactId>user-dao</artifactId> <packaging>jar</packaging> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <scope>test</scope> </dependency> </dependencies> </project>
user-service/pom.xml就变成了：
<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.cy.user</groupId> <artifactId>user-parent</artifactId> <version>0.0.1-SNAPSHOT</version> <relativePath>../user-parent/pom.xml</relativePath> </parent> <artifactId>user-service</artifactId> <packaging>jar</packaging> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aspects</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>com.cy.user</groupId> <artifactId>user-dao</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> </dependencies> </project>
user-web/pom.xml就变成了：
<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> <parent> <groupId>com.cy.user</groupId> <artifactId>user-parent</artifactId> <version>0.0.1-SNAPSHOT</version> <relativePath>../user-parent/pom.xml</relativePath> </parent> <artifactId>user-web</artifactId> <packaging>war</packaging><!-- 默认是jar，web项目是war --> <dependencies> <!-- 添加Servlet支持 --> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> </dependency> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>javax.servlet.jsp-api</artifactId> </dependency> <!-- 添加jstl支持 --> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> </dependency> <!-- 添加Spring支持 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> </dependency> <dependency> <groupId>com.cy.user</groupId> <artifactId>user-service</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <scope>test</scope> </dependency> </dependencies> <build> <finalName>user-web</finalName> </build> </project>
查看项目下的maven dependencies依赖jar包，版本都是从user-parent继承下来的；
运行项目，http://localhost:8080/user-web/index.jsp，正常访问ok；
tips：
运行项目出了点问题，把user-dao下面的com.cy.user.mappers包移到src/main/resources下面去了；因为xml不是java文件，编译的时候没编译进去，插件支持的不是很好；
------
