Question

我尝试使用mvn help：effective-pom命令在示例应用程序上生成有效的pom。 http://books.sonatype.com/mvnref-book/reference/pom-relationships-sect-pom.html 在这篇文章中，它说有效的pom是超级pom和应用程序pom之间的合并。

但是，当我看到我的有效pom时，它包含的元素不包含在超级pom或有效pom中。

还有其他因素决定什么会影响到有效的pom。

下面是超级pom和应用程序pom，这两个pom都没有mavne-jar-plugin或maven-compiler-plugin，但在我的有效pom中，我可以在构建部分看到这些插件。那么它是如何被添加的呢？

提前感谢您澄清此问题的任何帮助

超级POM

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<!-- START SNIPPET: superpom -->
<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>
<!-- END SNIPPET: superpom -->

申请POM

<project>
    <modelVersion>4.0.0</modelVersion>
    <groupId>org.sonatype.mavenbook.ch08</groupId>
    <artifactId>simplest-project</artifactId>
    <packaging>jar</packaging>
    <version>1</version>
</project>

有效的pom

Answer 1

有效POM由超级POM +应用程序POM + settings.xml内容+默认情况下绑定到生命周期的插件组成，基于所选的打包类型（因此，基于应用程序POM中的一个元素）。

您询问了maven-jar-plugin和maven-compiler-plugin。默认情况下，这些绑定到生命周期，因为您的应用程序POM指定了jar打包。

您可以在$YOUR_REPO_LOCATION\org\apache\maven\maven-core\3.0.x\maven-core-3.0.x.jar\META-INF\plexus\components.xml或documentation中看到默认绑定。

Answer 2

如果我没记错的话，有效的POM意味着要使用的实际POM。

在超级POM中加入设置是其中的一部分。它还包括许多其他内容，例如应用父POM，应用配置文件，替换属性等等。

我认为如果您能够提供一些您认为来自不在哪里的设置，那么我们可以更好地确定它们来自哪里。

有效 - pom是超级pom和应用程序POM之间的合并

2 个答案: