<p>I am looking for a Dataflow / Concurrent Programming API for Java.<br>
I know there's <a href="http://www.pervasivedatarush.com/" rel="noreferrer">DataRush</a>, but it's not free. What I'm interested in specifically is multicore data processing, and not distributed, which rules out <a href="http://en.wikipedia.org/wiki/MapReduce" rel="noreferrer">MapReduce</a> or <a href="http://en.wikipedia.org/wiki/Hadoop" rel="noreferrer">Hadoop</a>.<br>
Any thoughts?<br>
Thanks,
Rollo</p>

Does the built in Java
concurrent
package meet your needs?  It's a very nice package, built in ThreadPools, CopyOnWriteCollections, Executors, Future.  We use it to process large volumns of data in thread pools.