Java Sound Resources: Applications: Answering Machine

Web-based answering machine

From the session Applet Programming with the Java Sound API of the Java One 2001.


Using the Java Sound API in applets is one of the most interesting applications of the Java Sound API. Alas, it is also one of the most tricky. Different browser VMs, security restrictions and other variables make your task more difficult.

This application shows key techniques: a Web-based answering machine. It records speech, compresses it using a GSM 06.10 encoder and transfers it to a Web server. The owner of the answering machine can listen to the messages: they are loaded from the server, decoded to PCM and played on the local machine.

Special focus is on these issues:

  • Java Sound API security management

  • Signing applets

  • Invocation of the right VM

  • Encoding and decoding to and from GSM 06.10

  • Transferring sound data to and from a Web server


Caller - speak on the answering machine ! (Note that you must have enabled recording audio. See the slides for more information)

Owner - listen to the recorded messages


1378.pdf (280 kB)Presentation slides (right-click and select "save as..." to save it to disk)
am-src-<version>.zipComplete source code with incomplete instructions
am-<version>.jarCompiled classes. You still need tritonus_gsm.jar and tritonus_share.jar from Tritonus' plugin page.
CVSBrowse the source code online in the CVS repository.