The update site containing the most recent release is here: http://dist.codehaus.org/groovy/distributions/update/

• Go to: Help -> Software Updates -> Find and Install -> Search For New Features
• Click on New Remote Site
• Enter a name (eg: Groovy) in the Name field
• Copy the URL from above into the URL field and press OK (就是上面的update site ^_^)
• Check the new Groovy repository and press finish
• Under Select the Features to Install check the Groovy check box (be sure to get the latest version) and press Next
• Accept the agreement and press Next
• If the default location looks okay press Finish (this will download the plugin)
• If you get a warning that the plugin is unsigned click Install or Install All

This should download and install the Groovy plugin. It may require a restart of Eclipse to make sure it is loaded okay.(最好重启Eclipse哦)

If you're interested in trying the latest development version, the update site is: http://dist.codehaus.org/groovy/distributions/updateDev/

建立Groovy工程

To create a basic Groovy project in Eclipse perform. the following steps:

• Go to: File -> New -> Project
• Select Java Project and press Next
• In the Project Name field enter the name of your project (GroovyJava for this example)
• Under Project Layout select Create separate source and output folders and press Finish
• In the Package Explorer find the newly created project, right click, and select Groovy -> Add Groovy Nature

So far you should have a src folder, a bin-groovy folder, and several libraries. There is also a bin folder that was created by Eclipse, but is hidden due to exclusion filters. The next steps are needed to make the bin-groovy folder the default output folder, and to connect it to the src folder so that the debugger will know where to find the associated source and classes:

• In the Package Explorer, right click on the "GroovyJava" project, and select: Build Path -> Configure Build Path
• Select the Source tab and then use the Browse button to change the Default Output Folder from bin to bin-groovy
• Press OK, OK

This will expose the bin folder in the Package Explorer. I'm not sure why the plugin creates a bin-groovy directory. Perhaps there are other "bin" files that are best kept separate from the Groovy classes, or perhaps one of the original versions of Eclipse didn't create a "bin" directory automatically. Some day when someone has a clear idea of the usefulness of this, or lack thereof, we can clean up my instructions.
可以看到建立的Groovy工程也就是自动添加了groovy用到的一些jar包，在我们自己的工程中自己加入这些jar包也可以建立Groovy工程。