The java.nio stuff looks good.  The non-blocking sockets classes especially.  It looks similar in operation to the C ‘select’ function.  Wonder how long before some of the app. server products make use of it.  It will be interesting to see how much of a performance benefit there is compared to all the clever multi-threaded connection handling architectures that have evolved in the meantime.

Read more at:

http://www.onjava.com/pub/a/onjava/2002/09/04/nio.html