Apache Maven is a software project management and comprehension tool.
Based on the concept of a project object model (POM), Maven can manage
a project’s build, reporting and documentation from a central piece of
information.
Maven就是一个不需要手动导入依赖、项目打包和项目构建的工具
Maven中重要的两个关键词:继承和聚合。
继承:作用就是避免配置重复,对于子项目来说应该关心父项目是怎么样配置的。
聚合:字面理解就是“聚在一起合作完成工作”,就是将子模块聚集起来完成相应的项目需求
在多人使用Maven协作开发项目时,尤其是稍微上点规模的项目,每个RD的工作都细分到具体功能和模块,有些模块甚至还要单独部署。
我们假设有这样一个商城项目,包括以下几个模块:
商城前台(shop)
管理后台(admin)
数据库交互模块(dao)
通用业务模块(service)
接口模块(api)
通用工具(util)
其中shop和admin需要单独部署,dao、service、util你可能想要一些经验丰富的人来维护,如果使用一个应用来管理的话,所有的功能和模块都会耦合在一起,所有人都可以随意修改代码,这显然不是我们所期望的。
而且使用一个应用来管理的话,任何一个点的代码有变更,整个项目就需要重新build,使用模块化开发的另一个好处是如果dao的代码被修改,只需要重新build dao模块就可以了。web模块可以build成war,dao、service、util等可以build成jar,只需要配置好依赖关系,就可以实现模块间的解耦合。这样的设计才是遵循“高内聚,低耦合”设计原则的。
我们使用上面的例子进行演示,先进行合理的优化,我们希望dao和service作为通用的底层工具来使用,把它们合并成一个核心模块(core),build成core.jar,简单的Maven模块化项目结构如下:
———- mall //顶级项目
|—— pom.xml //packaging = pom
|—— mall-util //通用工具
| |— pom.xml //packaging = jar
|—— mall-core //核心模块
| |— pom.xml //packaging = jar
|—— mall-web-api //接口模块
| |— pom.xml //packaging = war
|—— mall-web-admin//管理后台
| |— pom.xml //packaging = war
|—— mall-web-shop//商城前台
| |— pom.xml //packaging = war
这些模块中api、admin、shop均是可以单独部署的web应用,相互之间没有依赖关系,但都依赖于core模块,而core模块依赖于util模块。接下来我们按照上述确定的结构来搭建项目结构。
创建项目
使用开发工具STS,其他工具也大同小异
(1) new -> Maven project 选择项目放置的地点 和勾选 create a simple project ,命名study
注意:父项目要使用 pom 方式进行packaging, 有三种 默认是 jar ,还有一种是web项目的war
(2)父项目建立好之后,开始建立子模块 new 一个 Maven module
命名为study-dao,parent为 study
选择quickstart
groupID 要和父项目一致,点击finish
查看一下study-dao的pom.xml
查看一下study的pom.xml
(3)同上一样的方式建立 study-service
只是注意 study-service 模块需要引入 study-dao,在study-service模块的pom.xml 文件中加上
spring-context也需要用到,先加上
<dependencies>
<dependency>
<groupId>com.studygroupId>
<artifactId>study-daoartifactId>
<version>0.0.1-SNAPSHOTversion>
dependency>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<version>3.8.1version>
<scope>testscope>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-contextartifactId>
<version>4.3.12.RELEASEversion>
dependency>
dependencies>
(4)建立 study-web 模块同上有一点不同,就是他是webapp ,需要打包成war
刚建立的时候会有报错,不要紧,加上 run server就可以
study-web的pom.xml 添加依赖, 整合SSM框架
<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>4.0.0modelVersion>
<parent>
<groupId>com.studygroupId>
<artifactId>studyartifactId>
<version>0.0.1-SNAPSHOTversion>
parent>
<groupId>com.studygroupId>
<artifactId>study-webartifactId>
<version>0.0.1-SNAPSHOTversion>
<packaging>warpackaging>
<name>study-web Maven Webappname>
<url>http://maven.apache.orgurl>
<properties>
<spring.version>4.3.12.RELEASEspring.version>
<servlet.version>3.1.0servlet.version>
<commons-codec>1.10commons-codec>
<mybatis.version>3.4.4mybatis.version>
<mybatis-spring>1.3.0mybatis-spring>
<c3p0>0.9.5.2c3p0>
<commons-logging>1.1commons-logging>
<mysql-connector-java>5.1.41mysql-connector-java>
<mybatis-generator-core>1.3.2mybatis-generator-core>
<pagehelper>5.0.0pagehelper>
<jackson>2.9.0jackson>
<jstl>1.2jstl>
properties>
<dependencies>
<dependency>
<groupId>com.studygroupId>
<artifactId>study-daoartifactId>
<version>0.0.1-SNAPSHOTversion>
dependency>
<dependency>
<groupId>com.studygroupId>
<artifactId>study-serviceartifactId>
<version>0.0.1-SNAPSHOTversion>
dependency>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<version>3.8.1version>
<scope>testscope>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>${servlet.version}version>
<scope>providedscope>
dependency>
<dependency>
<groupId>commons-codecgroupId>
<artifactId>commons-codecartifactId>
<version>${commons-codec}version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatisartifactId>
<version>${mybatis.version}version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatis-springartifactId>
<version>${mybatis-spring}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-coreartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-contextartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-beansartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-aopartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-aspectsartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-jdbcartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-txartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-ormartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webmvcartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>commons-logginggroupId>
<artifactId>commons-loggingartifactId>
<version>${commons-logging}version>
dependency>
<dependency>
<groupId>com.mchangegroupId>
<artifactId>c3p0artifactId>
<version>${c3p0}version>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>${mysql-connector-java}version>
dependency>
<dependency>
<groupId>org.mybatis.generatorgroupId>
<artifactId>mybatis-generator-coreartifactId>
<version>${mybatis-generator-core}version>
dependency>
<dependency>
<groupId>com.github.pagehelpergroupId>
<artifactId>pagehelperartifactId>
<version>${pagehelper}version>
dependency>
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-databindartifactId>
<version>${jackson}version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>jstlartifactId>
<version>${jstl}version>
dependency>
<dependency>
<groupId>javax.servlet.jspgroupId>
<artifactId>jsp-apiartifactId>
<version>2.2version>
<scope>providedscope>
dependency>
dependencies>
<build>
<finalName>study-webfinalName>
build>
project>
(5)study-web 的web.xml 的配置
<web-app>
<display-name>Archetype Created Web Applicationdisplay-name>
<context-param>
<param-name>log4jConfigLocationparam-name>
<param-value>classpath:log4j.propertiesparam-value>
context-param>
<context-param>
<param-name>log4jRefreshIntervalparam-name>
<param-value>60000param-value>
context-param>
<listener>
<listener-class>
org.springframework.web.util.Log4jConfigListener
listener-class>
listener>
<servlet>
<servlet-name>springservlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
<init-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:spring-mvc.xml;classpath:applicationContext.xmlparam-value>
init-param>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>springservlet-name>
<url-pattern>/*url-pattern>
servlet-mapping>
web-app>
log4j.properties的配置
log4j.rootLogger=INFO,Console,File
#\u5B9A\u4E49\u65E5\u5FD7\u8F93\u51FA\u76EE\u7684\u5730\u4E3A\u63A7\u5236\u53F0
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.Target=System.out
#\u53EF\u4EE5\u7075\u6D3B\u5730\u6307\u5B9A\u65E5\u5FD7\u8F93\u51FA\u683C\u5F0F\uFF0C\u4E0B\u9762\u4E00\u884C\u662F\u6307\u5B9A\u5177\u4F53\u7684\u683C\u5F0F
log4j.appender.Console.layout = org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=[%c] - %m%n
#\u6587\u4EF6\u5927\u5C0F\u5230\u8FBE\u6307\u5B9A\u5C3A\u5BF8\u7684\u65F6\u5019\u4EA7\u751F\u4E00\u4E2A\u65B0\u7684\u6587\u4EF6
log4j.appender.File = org.apache.log4j.RollingFileAppender
#\u6307\u5B9A\u8F93\u51FA\u76EE\u5F55
log4j.appender.File.File = logs/study.log
#\u5B9A\u4E49\u6587\u4EF6\u6700\u5927\u5927\u5C0F
log4j.appender.File.MaxFileSize = 10MB
# \u8F93\u51FA\u6240\u4EE5\u65E5\u5FD7\uFF0C\u5982\u679C\u6362\u6210DEBUG\u8868\u793A\u8F93\u51FADEBUG\u4EE5\u4E0A\u7EA7\u522B\u65E5\u5FD7
log4j.appender.File.Threshold = ALL
log4j.appender.File.layout = org.apache.log4j.PatternLayout
log4j.appender.File.layout.ConversionPattern =[%p] [%d{yyyy-MM-dd HH\:mm\:ss}][%c]%m%n
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:mvc="http://www.springframework.org/schema/mvc"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
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-4.3.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">
<mvc:annotation-driven/>
<context:property-placeholder location="classpath:mysql.properties" />
<bean class="com.mchange.v2.c3p0.ComboPooledDataSource" id="dataSource">
<property name="driverClass" value="${driverClass}">property>
<property name="jdbcUrl" value="${url}">property>
<property name="user" value="${user}">property>
<property name="password" value="${password}">property>
bean>
<bean class="org.mybatis.spring.SqlSessionFactoryBean" id="sqlSessionFactory">
<property name="dataSource" ref="dataSource">property>
<property name="configLocation" value="classpath:mybatis.xml">property>
<property name="mapperLocations" value="classpath:com/study/demo/mapping/*.xml">property>
bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory">property>
<property name="basePackage" value="com.study.demo.dao">property>
bean>
<bean class="org.springframework.jdbc.datasource.DataSourceTransactionManager" id="transactionManager">
<property name="dataSource" ref="dataSource">property>
bean>
<tx:annotation-driven transaction-manager="transactionManager"/>
beans>
spring-mvc.xml
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd ">
<bean id="mappingJacksonHttpMessageConverter"
class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>text/html;charset=UTF-8value>
list>
property>
bean>
<mvc:annotation-driven>
<mvc:message-converters register-defaults="true">
<bean
class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"
p:supportedMediaTypes="*/*" />
mvc:message-converters>
mvc:annotation-driven>
<bean
class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="messageConverters">
<list>
<ref bean="mappingJacksonHttpMessageConverter" />
list>
property>
bean>
<mvc:resources mapping="/resources/**" location="/resources/" />
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass"
value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/views/" />
<property name="suffix" value=".jsp" />
bean>
<mvc:annotation-driven />
<context:component-scan base-package="com.study.demo.dao" />
<context:component-scan base-package="com.study.demo.service.impl" />
<context:component-scan base-package="com.web.controller" />
<aop:aspectj-autoproxy proxy-target-class="true" />
<context:annotation-config />
beans>
mysql.properties
driverClass=com.mysql.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8
user=root
password=123456
mybatis.xml
<configuration>
<settings>
<setting name="lazyLoadingEnabled" value="true" />
settings>
configuration>
(5)实现一个简单逻辑,使项目能运行起来
study-dao 模块 单表的简单CRUD,不多说
study-web 模块,写一个Controller,测试下
ok,都写完了,我们就可以开始运行 study-web项目了,同平常运行非模块的的项目一样,右击study-web项目名,选择run as -> run on server, 选择Tomcat,开始运行
随后访问http://localhost:8080/study-web/aa,得到预期结果