Maven文件配置解析和常见内容

我们先看一个简单的例子：

[html] view
plaincopy





<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">
<!-- maven model version -->

<modelVersion>4.0.0</modelVersion>

<!-- project group id & artifact id -->

<groupId>com.freesoft.mvn-webapp</groupId>

<artifactId>mvnwebapp</artifactId>

<!-- packing type -->

<packaging>war</packaging>

<!-- version -->

<version>1.0-SNAPSHOT</version>

<name>mvnwebapp Maven Webapp</name>

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

<dependencies>

<!-- JUnit -->

<dependency>

<groupId>junit</groupId>

<artifactId>junit</artifactId>

<version>4.11</version>

<scope>test</scope>

</dependency>

</dependencies>

<build>

<finalName>mvnwebapp</finalName>

<pluginManagement>

<plugins>

<plugin>

<groupId>org.apache.tomcat.maven</groupId>

<artifactId>tomcat7-maven-plugin</artifactId>

<version>2.1</version>

<configuration>

<tomcat-url>http://localhost:8080/manager/html</tomcat-url>

<server>tomcat_localtest</server>

</configuration>

</plugin>

</plugins>

</pluginManagement>

</build>

<properties>

<struts.version>2.3.15</struts.version>

<mysql.version>5.1.29</mysql.version>

<hibernate.version>4.3.1.Final</hibernate.version>

</properties>

</project>

下面分段讲解。

1. 基本信息

modelVersion	Maven模块版本，目前我们一般都取值4.0.0
groupId	整个系统的名称。
artifactId	子模块名称。
packaging	打包类型，可取值：jar,war等等，这个配置用于package的phase，具体可以参见package运行的时候启动的plugin，后面有机会我们会讲述如何配置打包的插件。

2. dependencies

依赖关系。实际上pom之间存在好三种关系：继承、依赖、聚合。我们先讲依赖，这也是最重要的关系。

groupId	依赖项的groupId
artifactId	依赖项的artifactId
version	依赖项的版本
scope	依赖项的适用范围： compile，缺省值，适用于所有阶段，会随着项目一起发布。 provided，类似compile，期望JDK、容器或使用者会提供这个依赖。如servlet.jar。 runtime，只在运行时使用，如JDBC驱动，适用运行和测试阶段。 test，只在测试时使用，用于编译和运行测试代码。不会随项目发布。 system，类似provided，需要显式提供包含依赖的jar，Maven不会在Repository中查找它。 之前例子里的junit就只用在了test中。
exclusions	排除项目中的依赖冲突时使用。

2.1 关于排除依赖冲突

我们可能经常会遇到这样一个问题：我们的项目有两个依赖项：A & B，而且A和B同时依赖了C，但不是同一个版本。那么我们怎么办呢？

2.1.1 添加检查插件

[html] view
plaincopy





<reporting>

<plugins>

<plugin>

<groupId>org.apache.maven.plugins</groupId>

<artifactId>maven-project-info-reports-plugin</artifactId>

</plugin>

</plugins>

</reporting>

然后运行：mvn project-info-reports:dependencies，来查看依赖项报告。

2.1.2 去除依赖项

如果我们需要在某个dependency中去除某个依赖项，直接这样即可：

[html] view
plaincopy





<!-- Struts2 -->

<dependency>

<groupId>org.apache.struts</groupId>

<artifactId>struts2-core</artifactId>

<version>${struts.version}</version>

<exclusions>

<exclusion>

<groupId>org.freemarker</groupId>

<artifactId>freemarker</artifactId>

</exclusion>

</exclusions>

</dependency>

3. 继承

我的repository下面有个例子就直接拿来用了：

[html] view
plaincopy





<modelVersion>4.0.0</modelVersion>

<parent>

<groupId>com.thoughtworks.xstream</groupId>

<artifactId>xstream-parent</artifactId>

<version>1.4.3</version>

</parent>

<artifactId>xstream</artifactId>

<packaging>jar</packaging>

<name>XStream Core</name>

其中的parent表示父pom是com.thoughtworks.xstream的xstream-parent的1.4.3版本。继承关系比较简单，这里不做过多介绍。

4. 聚合

我们可以通过一个大的项目来整合各个小的模块：

[html] view
plaincopy





<modules>

<module>my-app</module>

</modules>

5. 属性

属性表述类似于EL表达式，ANT中也同样有，所以我们的properties字段可以这样使用：

[html] view
plaincopy





<!-- mysql -->

<dependency>

<groupId>mysql</groupId>

<artifactId>mysql-connector-java</artifactId>

<version>${mysql.version}</version>

</dependency>

6. 构建

6.1 plugin

Plugin的配置如下：

[html] view
plaincopy





<pluginManagement>

<plugins>

<plugin>

<groupId>org.apache.tomcat.maven</groupId>

<artifactId>tomcat7-maven-plugin</artifactId>

<version>2.1</version>

<configuration>

<tomcat-url>http://localhost:8080/manager/html</tomcat-url>

<server>tomcat_localtest</server>

</configuration>

</plugin>

</plugins>

</pluginManagement>

我们可以看到同样要哟偶groupId、artifactId、version还有一些配置参数。

6.2 resource

指定你在Build时需要的资源文件：

[html] view
plaincopy





<resources>

<resource>

<targetPath>WEB-INF/resource</targetPath>

<!-- 不对文件中的表达式进行处理 -->

<filtering>false</filtering>

<directory>${basedir}/src/test/resources</directory>

<includes>

<include>include.xml</include>

</includes>

<excludes>

<exclude>exclude.xml</exclude>

</excludes>

</resource>

</resources>

ok，基本上就是这么多，后续有什么疑问也请大家留言。

Maven继承SSH

1. 集成Struts2

1.1 修改pom.xml

在dependencies中添加：

[html] view
plaincopy





<!-- freemarker -->

<dependency>

<groupId>org.freemarker</groupId>

<artifactId>freemarker</artifactId>

<version>2.3.18</version>

</dependency>

<!-- Struts2 -->

<dependency>

<groupId>org.apache.struts</groupId>

<artifactId>struts2-core</artifactId>

<version>${struts.version}</version>

</dependency>

然后添加properties段：

[html] view
plaincopy





<properties>

<struts.version>2.3.15</struts.version>

</properties>

1.2 修改web.xml

去WEB-INF目录找到web.xml文件并添加：

[html] view
plaincopy





<filter>

<filter-name>struts2</filter-name>

<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>

</filter>

<filter-mapping>

<filter-name>struts2</filter-name>

<url-pattern>/*</url-pattern>

</filter-mapping>

1.3 添加Action

在src/main/java目录下添加Action:

[java] view
plaincopy





package com.freesoft.action;

import com.opensymphony.xwork2.ActionSupport;

public class TestAction extends ActionSupport {

private String username;

private String password;

@Override

public String execute() throws Exception {

return super.execute();

}

public String getUsername() {

return username;

}

public void setUsername(String username) {

this.username = username;

}

public String getPassword() {

return password;

}

public void setPassword(String password) {

this.password = password;

}

}

1.4 添加struts.xml

去src/main/resources目录添加struts.xml文件：

[html] view
plaincopy





<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE struts PUBLIC

"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"

"http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>

<package name="default" extends="struts-default">

<action name="test" class="com.freesoft.action.TestAction">

<result>/result.jsp</result>

</action>

</package>

</struts>

1.5 添加jsp

最后添加两个jsp，其中一个test.jsp

[html] view
plaincopy





<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<%@ taglib prefix="s" uri="/struts-tags"%>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<base href="<%=basePath%>">

<title>My JSP 'input.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">

<meta http-equiv="cache-control" content="no-cache">

<meta http-equiv="expires" content="0">

<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

<meta http-equiv="description" content="This is my page">

<!--

<link rel="stylesheet" type="text/css" href="styles.css">

-->

</head>

<body>

<s:form action="test.action">

<s:textfield name="username" label="username"></s:textfield>

<s:password name="password" label="password"></s:password>

<s:submit value="submit"></s:submit>

</s:form>

</body>

</html>

最后建立一个result.jsp

[html] view
plaincopy





<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<%@ taglib prefix="s" uri="/struts-tags"%>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<base href="<%=basePath%>">

<title>My JSP 'input.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">

<meta http-equiv="cache-control" content="no-cache">

<meta http-equiv="expires" content="0">

<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

<meta http-equiv="description" content="This is my page">

<!--

<link rel="stylesheet" type="text/css" href="styles.css">

-->

</head>

<body>

<s:property value="username"/><br>

<s:property value="password"/><br>

</body>

</html>

1.6 运行和调试

选择新建一个Maven Debug Configuration，然后goals输入tomcat7:redeploy即可。

需要调试的时候修改tomcat.bat(Windows下)或者tomcat.sh(linux下)文件，其中windows下修改为：

[plain] view
plaincopy





call "%EXECUTABLE%" jpda start %CMD_LINE_ARGS%

然后启动Tomcat，MyEclipse打开远程调试即可调试程序。

2. 集成Hibernate

2.1 集成MySQL Driver

首先我们集成MySQL的数据库驱动，我们在pom.xml中添加：

[html] view
plaincopy





<!-- mysql -->

<dependency>

<groupId>mysql</groupId>

<artifactId>mysql-connector-java</artifactId>

<version>${mysql.version}</version>

</dependency>

2.2 集成Hibernate

同样修改pom.xml：

[html] view
plaincopy





<!-- Hibernate -->

<dependency>

<groupId>org.hibernate</groupId>

<artifactId>hibernate-core</artifactId>

<version>${hibernate.version}</version>

</dependency>

properties段：

[html] view
plaincopy





<properties>

<struts.version>2.3.15</struts.version>

<mysql.version>5.1.29</mysql.version>

<hibernate.version>4.3.1.Final</hibernate.version>

</properties>

2.3 添加hibernate.cfg.xml

在/src/resource中添加hibernate.cfg.xml，内容是：

[html] view
plaincopy





<?xml version='1.0' encoding='UTF-8'?>

<!DOCTYPE hibernate-configuration PUBLIC

"-//Hibernate/Hibernate Configuration DTD 3.0//EN"

"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools. -->

<hibernate-configuration>

<session-factory>

<!-- 连接url -->

<property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property>

<!-- 用户名 -->

<property name="connection.username">root</property>

<!-- 密码 -->

<property name="connection.password">root</property>

<!-- 驱动 -->

<property name="connection.driver_class">com.mysql.jdbc.Driver</property>

<!-- 方言 -->

<property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>

<property name="show_sql">true</property>

<!-- <property name="format_sql">true</property> -->

<mapping resource="hbm/User.hbm.xml" />

</session-factory>

</hibernate-configuration>

然后添加源代码目录：src/test/java和src/test/resources，并且将其加入到工程的源代码目录中。

2.4 添加测试

添加hbm.xml：

[html] view
plaincopy





<?xml version="1.0" encoding="utf-8"?>

<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<!--

Mapping file autogenerated by MyEclipse Persistence Tools

-->

<hibernate-mapping>

<class name="com.freesoft.bean.User" table="user" catalog="hibernate">

<id name="id" type="long">

<column name="id" />

<generator class="increment" />

</id>

<property name="username" type="string">

<column name="username" length="50" />

</property>

<property name="password" type="string">

<column name="password" length="50" />

</property>

<property name="telephone" type="integer">

<column name="telephone" />

</property>

<property name="gender" type="character">

<column name="gender" length="1" />

</property>

<property name="graduation" type="boolean">

<column name="graduation" />

</property>

<property name="birthday" type="date">

<column name="birthday" length="10" />

</property>

<property name="marryTime" type="timestamp">

<column name="marryTime" length="19" />

</property>

<property name="file" type="blob">

<column name="file" />

</property>

</class>

</hibernate-mapping>

然后编写测试代码。

[java] view
plaincopy





package com.freesoft.test;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.InputStream;

import java.io.OutputStream;

import java.sql.Blob;

import java.sql.Timestamp;

import org.hibernate.Hibernate;

import org.hibernate.Session;

import org.hibernate.Transaction;

import org.junit.Test;

import com.freesoft.bean.User;

import com.freesoft.util.db.HibernateUtil;

public class TestUser {

@Test

public void testAdd() {

Session session = HibernateUtil.getSession();

Transaction tx = null;

try {

User user = new User();

user.setUsername("张三");

user.setPassword("password");

user.setGender('F');

user.setBirthday(new java.sql.Date(new java.util.Date().getTime()));

user.setGraduation(true);

user.setTelephone(1234567890);

user.setMarryTime(new Timestamp(new java.util.Date().getTime()));

InputStream ins = new FileInputStream(new File("src/test/resources/test.xml"));

Blob file = Hibernate.getLobCreator(session).createBlob(ins, ins.available());

user.setFile(file);

tx = session.beginTransaction();

session.save(user);

tx.commit();

} catch (Exception e) {

e.printStackTrace();

} finally {

HibernateUtil.closeSession(session);

}

}

@Test

public void testGet() {

Session session = HibernateUtil.getSession();

Transaction tx = null;

try {

tx = session.beginTransaction();

User user = (User) session.get(User.class, 1L);

Blob file = user.getFile();

long length = file.length();

byte[] buf = file.getBytes(1, (int) length);

OutputStream outs = new FileOutputStream(new File("src/test/resources/111.xml"));

outs.write(buf);

outs.flush();

outs.close();

tx.commit();

} catch (Exception e) {

e.printStackTrace();

} finally {

HibernateUtil.closeSession(session);

}

}

}

注意这里为了避免由于文件内容是中文引起的"Data too long for column 'file' at row 1"错误，我没有将file字段设置为byte[]而是设置为了Blob类型。

再新建一个maven的debug configuration，目录选择工程目录，goals选择test，然后run。

3. 集成Spring

[html] view
plaincopy





<dependencies>

<dependency>

<groupId>org.springframework</groupId>

<artifactId>spring-context</artifactId>

<version>4.0.2.RELEASE</version>

<scope>runtime</scope>

</dependency>

</dependencies>