I know you can but it's not clean. Also with Groovy on Grails early on there was some issues with timeouts if you're applicant wasn't popular, that was until GA

I know you can but it's not clean. Also with Groovy on Grails early on there was some issues with timeouts if you're applicant wasn't popular, that was until GAE allowed to run a hot instance. Probably why it didn't have an uptake. Also, anyone who is doing javascript is probably avoiding java and doesn't want to figure out how to put the right files together to deploy such an application.