posted 10 years ago
Groovy is essentially the next generation language in the Java family, so if you know Java it's easy to learn Groovy. As the previous commenter said, too, you can add Groovy incrementally to existing Java systems.
If you don't know Java but do know another OO language, then learning Groovy is still straightforward.
If you don't know any object oriented languages (and an increasing number of developers in my training classes fit that category), then you do have that hurdle to overcome, but at this point that process is pretty well understood.