maven--pom.xml详解

参考http://maven.apache.org/pom.html

Introduction

• POM : Project Object Model

top elements

<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>
  <!-- The Basics -->
  <groupId/>
  <artifactId/>
  <version/>
  <!-- value: pom, jar, maven-plugin, ejb, war, ear, rar, par; default: jar -->
  <packaging/>
  <dependencies/>
  <parent/>
  <dependencyManagement/>
  <modules/>
  <properties/>

  <!-- Build Settings -->
  <build/>
  <reporting/>

  <!-- More Project Information -->
  <name/>
  <description/>
  <url/>
  <inceptionYear/>
  <licenses/>
  <organization/>
  <developers/>
  <contributors/>

  <!-- Environment Settings -->
  <issueManagement/>
  <ciManagement/>
  <mailingLists/>
  <scm/>
  <prerequisites/>
  <repositories/>
  <pluginRepositories/>
  <distributionManagement/>
  <profiles/>
</project>

POM Relationships

1. Dependencies

• scope
  
  1. compile: default, available in all classpaths. propagated（传播）
  2. provided: available on the compilation and test classpath，not propagated
  3. runtime: in the runtime and test classpaths, but not the compile classpath.
  4. test: in the test compilation and execution phases.
  5. system: like provided

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.0</version>
      <type>jar</type>
      <scope>test</scope>
      <optional>true</optional>
      <!-- 区分jdk1.5,jdk1.4等 -->
      <classifier/>
      <systemPath/>
      <exclusions/>
    </dependency>
  </dependencies>

2. Inheritance

• 大部分元素都可以继承，除了一下几个：
  
  1. artifactId
  2. name
  3. prerequisites
• Super POM，所有pom的父对象。类似java.lang.Object

<!-- 可以使用 mvn help:effective-pom 可以对比源pom.xml来验证 -->
<project>
  <modelVersion>4.0.0</modelVersion>

  <repositories>
    <repository>
      <id>central</id>
      <name>Central Repository</name>
      <url>http://repo.maven.apache.org/maven2</url>
      <layout>default</layout>
      <snapshots>
        <enabled>false</enabled>
      </snapshots>
    </repository>
  </repositories>

  <pluginRepositories>
    <pluginRepository>
      <id>central</id>
      <name>Central Repository</name>
      <url>http://repo.maven.apache.org/maven2</url>
      <layout>default</layout>
      <snapshots>
        <enabled>false</enabled>
      </snapshots>
      <releases>
        <updatePolicy>never</updatePolicy>
      </releases>
    </pluginRepository>
  </pluginRepositories>

  <build>
    <directory>${project.basedir}/target</directory>
    <outputDirectory>${project.build.directory}/classes</outputDirectory>
    <finalName>${project.artifactId}-${project.version}</finalName>
    <testOutputDirectory>${project.build.directory}/test-classes</testOutputDirectory>
    <sourceDirectory>${project.basedir}/src/main/java</sourceDirectory>
    <scriptSourceDirectory>src/main/scripts</scriptSourceDirectory>
    <testSourceDirectory>${project.basedir}/src/test/java</testSourceDirectory>
    <resources>
      <resource>
        <directory>${project.basedir}/src/main/resources</directory>
      </resource>
    </resources>
    <testResources>
      <testResource>
        <directory>${project.basedir}/src/test/resources</directory>
      </testResource>
    </testResources>
    <pluginManagement>
      <!-- NOTE: These plugins will be removed from future versions of the super POM -->
      <!-- They are kept for the moment as they are very unlikely to conflict with lifecycle mappings (MNG-4453) -->
      <plugins>
        <plugin>
          <artifactId>maven-antrun-plugin</artifactId>
          <version>1.3</version>
        </plugin>
        <plugin>
          <artifactId>maven-assembly-plugin</artifactId>
          <version>2.2-beta-5</version>
        </plugin>
        <plugin>
          <artifactId>maven-dependency-plugin</artifactId>
          <version>2.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-release-plugin</artifactId>
          <version>2.0</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>

  <reporting>
    <outputDirectory>${project.build.directory}/site</outputDirectory>
  </reporting>
  <profiles>
    <!-- NOTE: The release profile will be removed from future versions of the super POM -->
    <profile>
      <id>release-profile</id>

      <activation>
        <property>
          <name>performRelease</name>
          <value>true</value>
        </property>
      </activation>
      <build>
        <plugins>
          <plugin>
            <inherited>true</inherited>
            <artifactId>maven-source-plugin</artifactId>
            <executions>
              <execution>
                <id>attach-sources</id>
                <goals>
                  <goal>jar</goal>
                </goals>
              </execution>
            </executions>
          </plugin>
          <plugin>
            <inherited>true</inherited>
            <artifactId>maven-javadoc-plugin</artifactId>
            <executions>
              <execution>
                <id>attach-javadocs</id>
                <goals>
                  <goal>jar</goal>
                </goals>
              </execution>
            </executions>
          </plugin>
          <plugin>
            <inherited>true</inherited>
            <artifactId>maven-deploy-plugin</artifactId>
            <configuration>
              <updateReleaseInfo>true</updateReleaseInfo>
            </configuration>
          </plugin>
        </plugins>
      </build>
    </profile>
  </profiles>
</project>

3. Aggregation (聚合)

<modules>
    <module>my-project</module>
    <module>another-project</module>
</modules>

Properties

等同: http://blog.youkuaiyun.com/tmriver/article/details/78839236#Properties

Build

otter,mq打包，
http://www.cnblogs.com/yangxia-test/category/675579.html

Reporting