Xlet

An Xlet is very similar to a Java applet and is designed to support applications for Digital TV. Xlets, unlike applets, can be paused and resumed. The Xlet interface is part of Sun's JavaTV specification.

The interface for an Xlet is defined in the java.tv.xlet package:

public interface Xlet {
  public void initXlet(XletContext ctx)
    throws XletStateChangeException;

  public void startXlet()
    throws XletStateChangeException;

  public void pauseXlet();

  public void destroyXlet(boolean unconditional)
    throws XletStateChangeException;
}

A example of stub Xlet is

import javax.tv.xlet.XletStateChangeException;
import javax.tv.xlet.XletContext;
import javax.tv.xlet.Xlet;

public class BasicXlet implements Xlet {
    public BasicXlet () {}
    public void initXlet (XletContext context) throws XletStateChangeException {}
    public void startXlet () throws XletStateChangeException {}
    public void pauseXlet () {}
    public void destroyXlet (boolean unconditional) throws XletStateChangeException {}
}

The pause/resume feature is essential for a Set-top box (STB) environment, which has limited memory resources and restrictions on bandwidth from the headend provider.

The current practice and intent of the Xlet framework is to provide downloadable applications for Connected Device Configuration platforms. In particular, the BD-J platform uses Xlets as its programming framework.

External links

• "An introduction to Xlets". Interactive TV Web. 2005-09-14. Retrieved 2006-06-21. {{cite web}}: Check date values in: |date= (help)
• Sun Microsystems' Java TV
• A set-top box emulator for viewing Xlets on a PC