I was learning Scala at one point. I was reading Atomic Scala [1] (I'm a big fan of Bruce Eckel as I learned Java from one of his earlier books, and some C++ before that). And I also took the Coursera Course from Martin O on functional reactive programming with Scala. I don't remember what is was actually called...
I'm still into alternative languages that run on the JVM...however I went and learned Go Lang in a weekend and it meets a lot of my needs for building out newer services.
Also, for my team the overhead of learning another JVM language (we already use Groovy quite a bit) didn't seem worth it in the end, even though I was a bit of a fan of the Scala idea for a few months.
I might still learn Scala some day, but we're not even on Java 8 at my current job, and that would alleviate a lot of my current Java grievances....
Don't let your experience with Apache Groovy put you off upgrading to a new JVM language. I learnt Clojure after using Groovy for a few years -- Groovy 1.8 was the last version I used. I then looked at Haskell, and now I'm using Go.
I'm still into alternative languages that run on the JVM...however I went and learned Go Lang in a weekend and it meets a lot of my needs for building out newer services.
Also, for my team the overhead of learning another JVM language (we already use Groovy quite a bit) didn't seem worth it in the end, even though I was a bit of a fan of the Scala idea for a few months.
I might still learn Scala some day, but we're not even on Java 8 at my current job, and that would alleviate a lot of my current Java grievances....
[1] http://www.atomicscala.com/ebook/