THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
Context
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Maven plugins are described in
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,
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which
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is
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in
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general
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generated
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by
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...
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.
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Information
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for
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the
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generator
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are
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written
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as
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javadoc
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annotations
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in
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java
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source:
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.
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 and @Execute at class-level, @Parameter and @Component at field level
- java package: org.apache.maven.tools.plugin.annotations
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- (consistent
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- with
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...
- a new maven-plugin-tools-annotations
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- component
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- in
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Extractor:
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addition
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into
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existing
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New features
- use annotations from parents classes coming from reactors and external dependencies.
Implementation
Initial work done in trunk http://svn.apache.org/repos/asf/maven/plugin-tools/trunk/
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The maven-plugin-plugin
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version
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has
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been
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bump
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to
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3.0-SNAPSHOT.
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State
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of
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the
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development
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as
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of
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22/5/2012
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Following
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usage
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for
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a
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plugin
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developer
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is
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working,
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with
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annotations
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near
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previous
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javadoc
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tags:
| Code Block | ||||
|---|---|---|---|---|
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{code:java} import org.apache.maven.plugin.AbstractMojo; import org.apache.maven.plugins.annotations.ResolutionScope; import org.apache.maven.plugins.annotations.Component; import org.apache.maven.plugins.annotations.Execute; import org.apache.maven.plugins.annotations.InstanciationStrategy; import org.apache.maven.plugins.annotations.LifecyclePhase; import org.apache.maven.plugins.annotations.Mojo; import org.apache.maven.plugins.annotations.Parameter; /** * Mojo Description. @Mojo( name = "<goalName>" ) is the minimal required annotation. * @since <since-text> * @deprecated <deprecated-text> */ @Mojo( name = "<goalName>", aggregator = <false|true>, configurator = "<roleHint>", executionStrategy = "<once-per-session|always>", inheritByDefault = <true|false>, instantiationStrategy = InstanciationStrategy.<strategy>, defaultPhase = "<phaseName>", requiresDependencyResolution = ResolutionScope.<scope>, requiresDependencyCollection = ResolutionScope.<scope>, // (since Maven 3.0) requiresDirectInvocation = <false|true>, requiresOnline = <false|true>, requiresProject = <true|false>, requiresReports = <false|true>, // (unsupported since Maven 3.0) threadSafe = <false|true> ) // (since Maven 3.0) @Execute( goal = "<goalName>", phase = LifecyclePhase.<phase> lifecycle = "<lifecycleId>" ) public class MyMojo extends AbstractMojo { /** * @since <since-text> * @deprecated <deprecated-text> */ @Parameter( alias = "myAlias", property = "aProperty", defaultValue = "${anExpression}", readonly = <false|true> required = <false|true> ) private String parameter; /** * @since <since-text> * @deprecated <deprecated-text> */ @Component( role = MyComponentExtension.class, roleHint = "..." ) private MyComponent component; public void execute() { ... } } {code} h2. Improvement Idea |
Improvement Idea HBO-1
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rename
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roleHint
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to
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hint
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to
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match
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Plexus
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@Requirement
| Code Block | ||||
|---|---|---|---|---|
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{code:java} @Component( role = MyComponentExtension.class, hint = "..." ) private MyComponent component; {code} h2. Improvement Idea |
Improvement Idea HBO-2
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Remove
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readonly
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attribute
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from
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@Parameter
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(was
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used
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for
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Maven
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components
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like
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${project}
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to
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mark
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that
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it
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should
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not
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be
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configured
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by
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plugin
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user),
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and
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replace
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by
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a
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new
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attribute
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of
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@Component
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which
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is
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mutually
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exclusive
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with
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role+hint
| Code Block | ||||
|---|---|---|---|---|
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{code:java} @Component( expression = "project" ) private MavenProject project; {code} h2. Improvement Idea |
Improvement Idea HBO-3
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Introduce
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JSR-330,
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by
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requiring
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plugin
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developer
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to
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mark
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injected
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fields
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with
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standard
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@Inject
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and
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make
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@Parameter
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and
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@Component
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standard
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Qualifier.
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Costs
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more
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writing
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for
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plugin
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developer
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(these
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@Inject)
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without
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much
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win
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other
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than
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mark
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the
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intent
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in
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a
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standard
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way
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(and
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should
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change
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much
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for
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maven-plugin-tools)