Creating and using a maven archetype

The best way to create a maven archetype is to start with an existing project. In the maven project (simple or multiple-module) directory execute:

    mvn archetype:create-from-project

The archetype is created under target/generated-sources/archetypes with the following directory structure:

    +---src
        +---main
            +---resources
                +---archetype-resources
                ¦   +---src
                ¦       +---main
                ¦           +---java (directory containing your java sources)
                ¦           +---resources (directory containing your non-java sources)
                ¦           +---webapp
                ¦               +---META-INF
                ¦               +---WEB-INF
                ¦                   +---jsp
                ¦
                +---META-INF
                    +---maven (directory containing archetype-metadata.xml)

The archetype-metadata.xml can used used to further tune the archetype. This file describes filesets of the following format:

    <fileSets>
      <fileSet filtered="true" packaged="true" encoding="UTF-8">
        <directory>src/main/java</directory>
        <includes>
          <include>/*.xml</include>
          <include>/*.java</include>
        </includes>
      </fileSet>
    </fileSets>

If the filtered property is set to true then all ${reference} are resolved. The built-in references are: groupId,version,artifactId,rootArtifactId,package .... If packaged is set to true then a directory tree representing the package is created before the resources are copied. Remember these are Velocity templates so you should be able to use Velocity control statements (note: I've not tried these yet)

Once you are happy with the archetype you can execute mvn install to install the archetype. This archetype should now appear in the list when you execute mvn archetype:generate. You can release the archetype if you have your own remote repository. You will however need to create a achetype-catalog.xml if you want other users to use this archetype from your own remote repository. The archetype-catalog.xml file should look like the following:

    <?xml version="1.0" encoding="UTF-8"?>
    <archetype-catalog>
      <archetypes>
        <archetype>
          <groupId>my.group</groupId>
          <artifactId>an-archetype</artifactId>
          <version>0.0.1</version>
          <description>my example archetype</description>
          <repository>http://repository-host/nexus/content/repositories/releases</repository>
        </archetype>
      </archetypes>
    </archetype-catalog>

You can then use this archetype to create a project using the following command:

mvn archetype:generate -DarchetypeCatalog=http://<uri-path>/archetype-catalog.xml