The ressources (256MB memory) of the Raspberry are very limited, so I didn't really expect to make it work, but instead it was easy.
a simple
apt-get install openjdk-7-jdk
installs java. The same for groovy:
apt-get install groovy
It takes some seconds until the groovy shell starts up, but it makes a good impression.
Installing Grails was a little bit harder since it can't be installed through apt-get. But a
wget http://dist.springframework.org.s3.amazonaws.com/release/GRAILS/grails-2.0.4.zip unzip grails-2.0.4.zip
nearly did the job. You still have to set some environment variables and lower the memory needs through GROOVY_OPTS (I personally changed the settings directy in the startGroovy). After that it works! Slowly, but it works. Generating a page takes aprox 6 minutes :-)
