Java APIs

Hi all
I'm on a program of reading incoming image set through socket.

This works perfect for some time.
But after some time it gives an error

java.lang.OutOfMemoryError: Java heap space
        at java.awt.image.BufferedImage.getRGB(Unknown Source)
        at com.sun.kvem.midp.GraphicsBridge.loadImage(Unknown Source)
        at com.sun.kvem.midp.GraphicsBridge.createImageFromData(Unknown Source)
        at sun.reflect.GeneratedMethodAccessor14.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at com.sun.kvem.sublime.MethodExecution.process(Unknown Source)
        at com.sun.kvem.sublime.SublimeExecutor.processRequest(Unknown Source)
        at com.sun.kvem.sublime.SublimeExecutor.run(Unknown Source)

This is my client code

public class ChangeImage extends Thread
{

    private SocketConnection sock = null;
    private Image img = null;
    private CanvasKey canvas = null;
    private InputStream in = null;

    public ChangeImage(SocketConnection sock, Canvas canvas) throws IOException
    {
        this.sock = sock;
        this.canvas = (CanvasKey) canvas;
        in = sock.openInputStream();
    }

    public void run()
    {
        super.run();
        short length;

        while (true)
        {
            DataInputStream din = null;
            try
            {
                din = new DataInputStream(in);

                length = din.readShort();	// to determine next data packet size

                byte[] arr = new byte[length];  // next data packet store here

                din.readFully(arr);  //read image


                img = Image.createImage(arr, 0, arr.length);

                canvas.setImage(img);
                
                ChangeImage.sleep(50);
            }
            catch (Exception ex)
            {
                ex.printStackTrace();
            }
        }
    }
}

Can u please tell me y?