2 nice blog about create and unit test custom IO stream - http://www.mattryall.net/article.cgi?id=286 http://www.mattryall.net/article.cgi?id=285

Java sockets I/O: blocking, non-blocking and asynchronous - https://www.linkedin.com/pulse/java-sockets-io-blocking-non-blocking-asynchronous-aliaksandr-liakh