You code, you learn - Groovy to Java

Here is one mistake you might end up doing:

"I'll code in Groovy first and then convert to Java. It should be a piece of cake!"

Be prepared for a bitter and hard to chew cake!

Groovy is very loose on typing so you'll end up doing all sorts of accidental programming errors, for instance, you can easily use methods that are not accessible on a static context. Generics are also a pain.

To convert the code you will have to do major refactoring with redesign of the class hierarchies.

I wasted 2 weeks on a project when I had to convert a 200 class application from Groovy to Java.

You code, you learn!