java.lang.OutOfMemoryError: Java heap space

[vidjogamer]

Hi I keep getting this error.

java.lang.OutOfMemoryError: Java heap space

Im trying to make a basic remote desktop application, but I keep getting this error when I repeatedly create desktop images. Here is my code that causes the error. Any suggestions?

public void run()
{
Toolkit toolkit = Toolkit.getDefaultToolkit();
Robot robot;
Dimension dim = toolkit.getScreenSize();
Rectangle rect = new Rectangle((int)dim.getWidth(),(int)dim.getHeight() );
BufferedImage buff;
int counter = 0;
try
{
robot = new Robot();

while(true)
{

System.out.println(++counter);
buff = robot.createScreenCapture(rect);
icon = new ImageIcon(buff);
toClient.writeObject(icon);



Thread.sleep(20);


}
}
catch(Exception ex)
{
ex.printStackTrace();
}
}

[toadaly]

My guess is that you are creating objects faster than they are being garbage collected. To avoid this, increase your heap size using the -Xmx command line option, and add a gc cleanup request after each 'writeObject'.

Also, you may be duplicating pixels by creating an ImageIcon (unsure of it's implementation). You might try instead getRaster().getPixels() on the BufferedImage returned by the robot, and send a byte array instead of an ImageIcon.

If the problem persists, your only hope may be to gracefully deal with the memory errors.

[vidjogamer]

Yes, that was my guess as well. I tried increasing the heap size but after a while my machine began to lag significantly. How can I add a gc cleanup request?

Edit:
I put a System.gc() after the write object still with no luck.
I am running both the client and the server on the same machine. Do you think that could be the problem?

[toadaly]

Hmm. If System.gc isn't working, I'm wondering if there might be something in the "toClient" method that is causing references to persist. Are you by chance keeping some kind of a list of everything it sends?