Maven2 Binding to a custom Phase

Question

I have a custom plugin that is defined using the pom.xml

<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">
  <modelVersion>4.0.0</modelVersion>
  <groupId>pram.plugintest</groupId>
  <artifactId>pram.plugintest</artifactId>
  <packaging>maven-plugin</packaging>
  <version>1.1-SNAPSHOT</version>
  <name>pram.plugintest Maven Mojo</name>
  <url>http://maven.apache.org</url>
  <build>
        <plugins>
            <plugin>
                <artifactId>maven-plugin-plugin</artifactId>
                <version>2.3</version>
                <configuration>
                    <goalPrefix>blah</goalPrefix>
                </configuration>
            </plugin>
        </plugins>
      <resources>
          <resource>
              <directory>src/main/resources</directory>
          </resource>
      </resources>
    </build>
  <dependencies>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-plugin-api</artifactId>
      <version>2.0</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

Running

mvn blah:touch

Creates a text file in the target directory as expected. I now create a lifecycles.xml file in the resources directory specified in the pom

<lifecycles>
    <lifecycle>
        <id>touch</id>
        <phases>
            <phase>
                <id>package</id>
                <executions>
                    <execution>
                        <goals>
                            <goal>touch</goal>
                        </goals>
                    </execution>
                </executions>
            </phase>
        </phases>
    </lifecycle>
</lifecycles>

In another maven project, I would like to bind the running of mvn blah:touch to an execution task similar to this

...
<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>exec-maven-plugin</artifactId>
    <version>1.2.1</version>
    <executions>
        <execution>
        <id>test1</id>
        <phase>blah:touch</phase>
        <goals>
            <goal>java</goal>
        </goals>
        <configuration>
<mainClass>mainClass=org.sonatype.mavenbook.weather.Main</mainClass>
        </configuration>
    </execution>
</executions>
</plugin>
...

However running this creates the text file but doesn't attempt to run org.sonatype.mavenbook.weather.Main

Is this the correct approach?

Ultimately what I would like is to have multiple execution sections in the exec-maven-plugin that are not bound to the default phases. Logically it would look like this

...
<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>exec-maven-plugin</artifactId>
    <version>1.2.1</version>
    <executions>
        <execution>
        <id>test1</id>
        <phase>blah:touch</phase>
        <goals>
            <goal>java</goal>
        </goals>
        <configuration>
<mainClass>mainClass=org.sonatype.mavenbook.weather.Main</mainClass>
        </configuration>
    </execution>
<execution>
        <id>test2</id>
        <phase>blah:touch2</phase>
        <goals>
            <goal>java</goal>
        </goals>
        <configuration>
<mainClass>mainClass=org.sonatype.mavenbook.weather.SomeOtherClass</mainClass>
        </configuration>
    </execution>
</executions>
</plugin>
...

So if I run mvn blah:touch then org.sonatype.mavenbook.weather.Main will be executed and if I run mvn blah:touch2 then org.sonatype.mavenbook.weather.SomeOtherClass will be executed instead.

It seems like it should be straightforward to do but there's nothing in the documentation that seems to point out how to do this.

Answer 1

You can not use the exec-maven-plugin for this and you do not need the lifecycle.xml if you only would like to execute your plugin during a build.

To execute your plugin during a specific Maven phase, you simply have to add

   <plugins>
        <plugin>
            <groupId>your.group.id</groupId>
            <artifactId>your.artifact.id</artifactId>
            <executions>
                <execution>
                    <id>unique-execution-id</id>
                    <goals>
                        <goal>the.goal.of.your.plugin</goal>
                    </goals>
                    <phase>maven.phase</phase>
                    <configuration>
                     ....
                    </configuration>
                </execution>
             </executions>
        </plugin>
   </plugins>

Please specify the goal in the goal element without the prefix.

Did you read http://www.sonatype.com/books/mvnref-book/reference/writing-plugins-sect-plugins-lifecycle.html?