本篇給出maven3的pom文件樣例。包括：
- 項目打包方式；
- 項目如何打成可執行jar包；
- 如何預定義一些常量，如版本號；
- 生成站點（site），如生成javadoc文件；
- 如何自定義項目源代碼的主目錄；
- 如何自定義項目測試代碼的主目錄；
- 如何添加項目依賴的jar包，並指定依賴範圍；
- 如何添加可選依賴；
下面直接貼出樣例代碼。
<pre name="code" class="html"><pre name="code" class="html"><pre name="code" class="html"><?xml version="1.0" encoding="UTF-8"?>
<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>cn.pri.qk</groupId>
<artifactId>QSProject</artifactId>
<version>1.0-SNAPSHOT</version>
<name>A Test Project</name>
<!--定義項目的打包方式,可選值爲:jar（默認), war, pom, apk, 如果一個項目是父項目，那麼必須設置爲pom。-->
<packaging>jar</packaging>
<!--使用<properties>元素來定義一些常量,即便於統一修改,又能減少出錯的機率-->
<properties>
<project.version>1.0</project.version>
<jdk.version>1.8</jdk.version>
<springFramework.version>2.5.6</springFramework.version>
</properties>
<reporting>
<plugins>
<!--這個插件用來爲主目錄的代碼生成javadoc文件,可參見:
http://maven.apache.org/plugins/maven-site-plugin/examples/configuring-reports.html
-->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-javadoc-plugin</artifactId>
<version>2.9</version>
<reportSets>
<reportSet>
<!-- by default, id = "default" -->
<reports>
<!-- select non-aggregate reports -->
<report>javadoc</report>
<report>test-javadoc</report>
</reports>
</reportSet>
<reportSet>
<!-- aggregate reportSet, to define in poms having modules -->
<id>aggregate</id>
<inherited>false</inherited>
<!-- don't run aggregate in child modules -->
<reports>
<report>aggregate</report>
</reports>
</reportSet>
</reportSets>
</plugin>
</plugins>
</reporting>
<build>
<!-- 項目源代碼的主目錄 -->
<sourceDirectory>src/main/java</sourceDirectory>
<!-- 項目測試代碼的主目錄 -->
<testSourceDirectory>src/test/java</testSourceDirectory>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<!-- 這個插件用來將項目打成可運行的jar包 -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>1.2.1</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<transformers>
<transformer
implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
<resource>META-INF/spring.handlers</resource>
</transformer>
<transformer
implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
<resource>META-INF/spring.schemas</resource>
</transformer>
<transformer
implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer"> <!-- 指定可運行jar包的入口類 -->
<mainClass>cn.pri.qk.Main</mainClass>
</transformer>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
<!-- 添加一些依賴的jar包 -->
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.7</version>
<!-- 該依賴只對測試有效, 可選值爲:compile(默認值,在所有的classpath中均可用), provided, runtime, test, system. http://blog.sina.com.cn/s/blog_67aaf4440101dwr8.html-->
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.jdom</groupId>
<artifactId>jdom2</artifactId>
<version>2.0.6</version>
<scope>compile</scope>
</dependency>
<!--optional選項用來解決互斥的依賴。如下面這兩個依賴是可選依賴,但其他項目依賴當前項目時,該依賴不會被傳遞過去.使用可選依賴就意味着項目裏存在兩個或多個互斥的特性, 這不滿足單一職責的原則,所以應儘量避免使用可選依賴-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.10</version>
<optional>true</optional>
<!--<exclusions>元素用來移除當前依賴項所依賴的部分依賴項,因爲那些依賴項有可能是某個project的SNAPSHOT版本或需要收費-->
<exclusions>
<exclusion>
<groupId>mysql</groupId>
<artifactId>project</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>8.4-701.jdbc3</version>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<!--使用預定義好的常量-->
<version>${springFramework.version}</version>
</dependency>
</dependencies>
</project>
