How do you double buffer in java for a game?

Question

So in the game I\'m working on, I have a marble follow the mouse, but when it does this the screen flickers.

The background includes two jpegs and 9 rectangles. How

Answer 1

Double buffering is conceptually pretty simple, instead of drawing your objects one by one, you draw them on an image and then tell the renderer to draw that entire image. This eliminates the flickering.

Here's an example of how you might do this (source)

class DoubleBufferedCanvas extends Canvas {

    public void update(Graphics g) {
    Graphics offgc;
    Image offscreen = null;
    Dimension d = size();

    // create the offscreen buffer and associated Graphics
    offscreen = createImage(d.width, d.height);
    offgc = offscreen.getGraphics();
    // clear the exposed area
    offgc.setColor(getBackground());
    offgc.fillRect(0, 0, d.width, d.height);
    offgc.setColor(getForeground());
    // do normal redraw
    paint(offgc);
    // transfer offscreen to window
    g.drawImage(offscreen, 0, 0, this);
    }
}

Nowdays, you don't have to implement this yourself, you can use the BufferStrategy and releated classes. See lakam99's answer for an example of that .