Disable screen saver / sleep mode through a website

Question

I am working on a web application that needs to be active on the monitor sometimes for hours without anyone touch the computer.

The problem is that some computers have their screen saver, or worse - sleep mode while their inactive.

I'm trying to think of a way to bypass it. I searched for java applets or maybe a flash file that does only that. I found nothing, unfortunately.

I'm sorry for the too general question but I'm pretty helpless with this subject

Answer 1

I've written the Java applet for you. It will move the mouse cursor one pixel to the right and back every 59 seconds, effectively preventing the screen saver from kicking in.

Note that because of security restrictions this applet will need to be signed and granted the createRobot permission to work on the client, otherwise it will fail to initialize the Robot class. But that's a problem outside this question's scope.

import java.applet.Applet;
import java.awt.*;
import java.util.Timer;
import java.util.TimerTask;

/**
 * Moves the mouse cursor once in a minute to prevent the screen saver from
 * kicking in.
 */
public class ScreenSaverDisablerApplet extends Applet {

    private static final int PERIOD = 59;
    private Timer screenSaverDisabler;

    @Override
    public void start() {
        screenSaverDisabler = new Timer();
        screenSaverDisabler.scheduleAtFixedRate(new TimerTask() {
            Robot r = null;
            {
                try {
                    r = new Robot();
                } catch (AWTException headlessEnvironmentException) {
                    screenSaverDisabler.cancel();
                }
            }
            @Override
            public void run() {
                Point loc = MouseInfo.getPointerInfo().getLocation();
                r.mouseMove(loc.x + 1, loc.y);
                r.mouseMove(loc.x, loc.y);
            }
        }, 0, PERIOD*1000);
    }

    @Override
    public void stop() {
        screenSaverDisabler.cancel();
    }

}