Grails Maven Plugin is still non predictable and it’s 1.0 version supports only 1.1 version of Grails. 1.1-SNAPSHOT version supports grails 1.1.1 but there are still misunderstandings with Grails plugins are exist (Grails wants to store them in your user home, but  Grails Maven plugin wants them to be stored in your application dir).

As for now I’m trying to avoid using plugins from Grails, and include all libraries directly with Maven dependencies.

1. Make your maven know where to get grails-maven-plugin by editing your /.m2/settings.xml (create it if there is no one exist):

<settings>
    <pluginGroups>
        <pluginGroup>org.grails</pluginGroup>
    </pluginGroups>
</settings>

2. Go to secret place where you store you projects and run:

mvn org.apache.maven.plugins:maven-archetype-plugin:2.0-alpha-4:generate -DarchetypeGroupId=org.grails -DarchetypeArtifactId=grails-maven-archetype -DarchetypeVersion=1.0 -DgroupId=example -DartifactId=maven-grails-demo

3. Now open just generated pom.xml and make following changes:

  • change versions of grails-crud and grails-gorm from “1.1” to “1.1.1”
  • change grails-maven-plugin version from “1.0” to “1.1-SNAPSHOT”
4. Run “mvn initialize” from your project root.
5. One more trick, that should be applied for 1.1-SNAPSHOT version of grails-maven-plugin to make it work: add following dependency to your pom.xml (see http://jira.codehaus.org/browse/GRAILS-4574 for details):
<dependency>
    <groupId>org.tmatesoft.svnkit</groupId>
    <artifactId>svnkit</artifactId>
    <version>1.2.3.5521</version>
    <scope>runtime</scope>
</dependency>

6. Now, it’s time to import your maven project into Intellij IDEA (I recommend to use latest EAP http://www.jetbrains.net/confluence/display/IDEADEV/Maia+EAP). You can do it by “Create New Project → Import Project from External Model → Maven…”.

Pay attention to Facets that Idea will detect on project import finished. Hint: look in right bottom corner for round icon with “i” on it, if Idea won’t show you dialog window with detected facets. Facets detection is important to let Idea know that it’s Grails application.
Now close and reopen project again to let JetGroovy plugin use facets and treat application directories in a right way. You should see “Grails:maven-grails-demo” preselected in IDEA’s run/debug configurations combo. If it’s so – you on the right way and JetGroovy knows that it’s Grails application. If not – try to fix it in “module settings → facets”. If you didn’t make it – contact me, I’ll try to help.

You probably already tried to run application but all you’ve got was:
Exception in thread "main" java.lang.ClassNotFoundException: org.codehaus.groovy.grails.cli.support.GrailsStarter at java.net.URLClassLoader$1.run(URLClassLoader.java:200) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:307) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:252) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:169) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:87)
Don’t worry. It’s because grails-maven-plugin depends on grails-core which not contain GrailsStarter. It’s available in standalone Grails distribution. First of all you are still able to run grails application with “Maven Projects → maven-grails-demo → Plugins → grails → grails:run-app” or just by running “mvn grails:run-app” from project root. If you still want to run your application from run configuration in Idea you could or create run configuration from Maven goal, by clicking on with right button and selecting appropriate menu item or by installing standalone Grails and telling IDEA where it is.

Setting up standalone Grails for your application

  • Install Grails as described http://grails.org/Installation.
  • Go to module settings → Groovy → click “Add…” → Create new Grails SDK… → Tell Idea where your standalone Grails is → Click “Replace” (not “Add”, important) in dialog appeared
Now you able to run your Grails application directly from Idea with JetGroovy plugin. Enjoy ;)