maven-plugin-plugin/src/site/apt/examples/using-annotations.apt.vm

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 Using Plugin Tools Java5 Annotations
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 Olivier Lamy
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 2012-05-14
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~~ to you under the Apache License, Version 2.0 (the
~~ "License"); you may not use this file except in compliance
~~ with the License.  You may obtain a copy of the License at
~~
~~   http://www.apache.org/licenses/LICENSE-2.0
~~
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~~ software distributed under the License is distributed on an
~~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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~~ NOTE: For help with the syntax of this file, see:
~~ https://maven.apache.org/doxia/references/apt-format.html

Using Plugin Tools Java Annotations

 You can use Java annotations to generate the plugin descriptor file.

 <<NOTE>> With annotations, your Mojo super class does not have to be in the same project: provided that the superclass also uses annotations, it
 can now come from reactor projects or external dependencies. By default all dependencies are scanned, but this can be reduced with the <<<mojoDependencies>>>
 parameter. BUT as javadoc doclets are still useful for goals and parameters description, <<<@since>>> and <<<@deprecated>>>, the sources are still scanned. So if you use an external
 dependency, you must still provide an artifact with sources (<<<sources>>> classifier) to provide documentation (the tooling will skip error if this artifact 
 sources is missing).

* Annotations

  Information for plugin descriptor generation is specified using 4 annotations:

  * 2 class level annotations:

    * <<<@Mojo>>>: This annotation will mark your class as a Mojo,

    * <<<@Execute>>>: Used if your Mojo needs to fork a lifecycle,

    []

  * 1 field or method level annotations:

    * <<<@Parameter>>>: Used to configure your Mojo parameters,

    []

  * 1 field level annotations:

    * <<<@Component>>>: Used to configure injection of Plexus components or Maven context components.

    []

  []

  For more information on these annotations, see the
  {{{../../maven-plugin-tools-annotations/index.html#Supported_Annotations}corresponding documentation}}.

  Notice that Plugin Tools Java Annotations are named after Plugin Tools Javadoc Tags
  with following little differences:

*-------------------------------+---------------+
|| {{{../../maven-plugin-tools-java/index.html}Plugin Tools Javadoc Tags}} || {{{../../maven-plugin-tools-annotations/index.html}Plugin Tools Java Annotation}} ||
*-------------------------------+---------------+
| <<<@goal "goal-name">>>       | <<<@Mojo( name = "goal-name" )>>>
*-------------------------------+---------------+
| <<<@phase "\<phase-name\>">>> | <<<@Mojo( defaultPhase = LifecyclePhase.\<phase\> )>>>
*-------------------------------+---------------+

* POM configuration

  To use these Java annotations, add a dependency on
  <<<maven-plugin-annotations>>> to your pom, preferably with <<<provided>>> scope.

+-----+
<project>
  ...
  <packaging>maven-plugin</packaging>
  ...
  <dependencies>
    <!-- dependencies to annotations -->
    <dependency>
      <groupId>org.apache.maven.plugin-tools</groupId>
      <artifactId>maven-plugin-annotations</artifactId>
      <version>${project.version}</version>
      <scope>provided</scope> <!-- annotations are not used at runtime because @Retention(value=CLASS), they are needed only to build the plugin -->
    </dependency>
  </dependencies>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-plugin-plugin</artifactId>
        <version>${project.version}</version>
        <executions>
          <!-- if you want to generate help goal -->
          <execution>
            <id>help-goal</id>
            <goals>
              <goal>helpmojo</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  ...
  </build>
  ...
</project>
+-----+