this is a commercial version of what your looking for.
http://www.5cup.com/shareware/Internet_Utilities-Download_Managers-Web_Stream_Recorder_Pro-1.0.html
this page might shed some light if your doing it on your own.
http://docs.hp.com/en/6154/hp/telephony/media/Recorder.html
this page might shed some light on how to acheive it in java
http://forum.java.sun.com/thread.jspa?threadID=640091
this page will show you how to play the stream in java once you have it
http://www.developer.com/java/other/article.php/857411
this might shed some light ont he stream name
http://java.sun.com/j2se/1.3/docs/api/java/io/ObjectInputStream.GetField.html
I havent spent much time exploring them, but its probably a good start
If no-one gives your an answer to a question you have asked, consider:- Is your question clear.- Did you ask nicely.- Are you showing any effort to solve the problem yourself 