Context

Maven plugins are described in META-INF/maven/plugin.xml descriptor, which is in general generated by maven-plugin-plugin. Information for the generator are written as javadoc annotations in java source: see maven-plugin-tools-java.

Using java 5 annotations instead of javadoc ones have multiple benefits:

• compile-time checks for plugin metadata, with enums for some annotations
• inheritance support
• annotations are supported in most IDEs, providing code-completion and syntactic checks

see plexus-component-annotations for an example of such a work done on Plexus.

Existing implementations

Multiple implementations of such annotations exist:

• JFrog's Maven Anno Mojo: see the wiki or annotations source,
  the idea is having as much annotations as actual javadoc annotations, each with only 1 attribute
• Maven MNG-2521, with its proposal from 2007 providing a source branch and its annotations,
  the idea is having only 4 annotations each with multiple attributes: Goal + Execute and Parameter + Component

Proposal

Continue the work started on MNG-2521 before plugin-tools extraction from Maven Core.

Annotations:

• 4 annotations: @Mojo, @Execute, @Parameter and @Component
• java package: org.apache.maven.tools.plugin.annotations (consistent with maven-plugin-tools-api
• a new maven-plugin-tools-annotations component in plugin-tools

Extractor: addition into existing maven-plugin-tools-java

New features

• use annotations from parents classes coming from reactors and external dependencies.

Work started in branch http://svn.apache.org/repos/asf/maven/plugin-tools/branches/MPLUGIN-189/