Grape Maven

Groovy GrapeEngine that uses Maven API directly.

Motivation

Groovy's default GrapeEngine uses Apache Ivy. If you are primarily using Apache Maven, this means having to keep two separate jar repositories: %USERPROFILE%/.groovy/grapes and %USERPROFILE%/.m2/repository.

Sure, Ivy can be asked to resolve from local Maven repository, but for anything not available in the latter, it is still going to download and store the jars into its own repository. Also, anything that can be resolved from local Maven repository is going to be cached in its own repository as well.

Dealing with *-SNAPSHOT jars is another headache as well.

Tested on

• Groovy 2.2.2
• Java 1.7.0_75
• Windows 8.1
• Apache Maven 3.2.5's local repository

Usage instruction

1. Download the project (preferably tag).
2. Run mvn clean package assembly:single -DdescriptorId=jar-with-dependencies on the project.

• Requires Maven - but if you need this, you'd already have it ;)

3. Copy the resulting grape-maven-<version>-jar-with-dependencies.jar into $GROOVY_HOME/lib/.
4. To check if it works, run any Groovy script that contains @Grab("<group>:<module>:<version>") with groovy.grape.report.downloads turned on, e.g.:

C:\> groovy -Dgroovy.grape.report.downloads=true MyScript.groovy

You should see messages similar to this in console:

...
Resolving artifact org.jsoup:jsoup:jar:1.7.2
Resolved artifact org.jsoup:jsoup:jar:1.7.2 from central (http://repo1.maven.org/maven2, releases+snapshots)
Resolving artifact commons-io:commons-io:jar:2.2
Resolved artifact commons-io:commons-io:jar:2.2 from central (http://repo1.maven.org/maven2, releases+snapshots)
...

Troubleshooting

Since Groovy uses groovy.grape.GrapeIvy as the default GrapeEngine, and there is no extension mechanism, Grape Maven overrides this by supplying a fake groovy.grape.GrapeIvy (that redirects to GrapeMaven) in its jar.

For this to happen, grape-maven-<version>.jar has to be loaded before groovy-<version>.jar. In Windows, you shouldn't have to do anything special because I think jars are loaded based on name, and 'grape-maven' comes before 'groovy'.

But if for some reason this doesn't work (different platform, etc) what you can do is to remove groovy/grape/GrapeIvy.class from %GROOVY_HOME%/lib/groovy-<version>.jar (which you'd first backup somewhere safe, of course).

Milestones

• Supports @Grab("<group>:<module>:<version>")
• Supports Grape.grab([group: <group>, module: <module>, version: <version>])
• Supports groovy.grape.report.downloads flag
• Supports extension modules
• Allows Groovy Console (groovyConsole.bat) to start up