akka :(

I was interested up to the point where I saw I needed akka. I have no interest in dragging along all the scala dependancies that akka requires or writing my apps in scala. I guess thats why its “Programming Concurrency on the JVM” and not “Programming Concurrency in Java”.

As far as I can see the book gives examples in both Java and Scala regarding Akka Actors.

sure, but underneath, akka has scala as a dependancy amongst other things.

Stu, as Ersin mentioned, I present solutions using multiple JVM
languages including Java.

In Java we rely on quite a number of libraries for various tasks. Quite
a few of us care about the fluency of the libraries’ API, the ease of use,
reliability, and performance. If those satisfy your expectations, then
I think Akka is a great fit to solve your concurrency needs. If, for some
reason, it’s internal dependencies prohibit you from benefiting from this
quite excellent library, then neither the library nor this book will be use
to you.

Stu, why does Scala as a dependency bother you? You can use Akka from Java. Underneath the covers it has “scala-library.jar” along with seventeen other jars. These jars include projects like Netty, Protobuf, Jackson, Guice, etc.

The only Scala dependencies are the scala-library.jar, and sjson_*.jar. This is an implementation detail of Akka and is not exposed to the consumer of the API (unless you’d like it to be). I’m not sure why this troubles you.

Akka:

1. Has the best concurrency on the JVM
2. Great integration interfaces including Java
3. State of the art Scala
4. Polyglot language opportunities as described by Venkat

The Scala dependencies which enable all these capabilities are worth it.
So wake up and smell the roses.

You might find this book of interest: “Composable Futures with Akka 2.0”, available at http://slinnbooks.com/books/futures/