Example double-buffering using Canvas2D; excerpt from Project X.

DoubleBuffering.java

/*******************************
 * Example of double buffering
 * in Canvas2D
********************************/

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.util.*;

import javax.swing.*;

public class BufferingDemo extends Thread {
	private Graphics2D g2d; //initial buffer
	private Graphics2D b_g2d; //background graphics
	private Canvas canvas;
	private BufferStrategy strategy;
	private BufferedImage background;
	
	private boolean running = false;
	
	private GraphicsConfiguration cfg = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().getDefaultConfiguration();
	private Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
	
	public BufferingDemo() {
		running = true; //set the thread to on
		start(); //inherited method for initializing thread
	}
	public BufferedImage createBufferedImage(final int width, final int height, final boolean alpha) {
		return cfg.createCompatibleImage(width, height, alpha ? Transparency.TRANSLUCENT : Transparency.OPAQUE);
	}
	private Graphics2D getBuffer() { //return buffer for graphics
		if (g2d == null) try {
			g2d = (Graphics2D) strategy.getDrawGraphics();
		} catch (IllegalStateException e) {
			return null;
		}
		return g2d;
	}
	public void run() { //thread process to iterate
		b_g2d = (Graphics2D) background.getGraphics();
		main: while (running) {
			gameUpdate();
			do {
				Graphics2D bg = getBuffer(); //background
				if (!running) break main;
				render(b_g2d); //render to background graphics
				bg.drawImage(background, 0, 0, null);
			} while (!screenUpdate());
		}
		window.dispose(); //release system resources
	}
	public boolean screenUpdate() {
		g2d.dispose(); //release system resources
		g2d = null;
		try {
			strategy.show();
			Toolkit.getDefaultToolkit().sync();
			return (!strategy.contentsLost());
		} catch (NullPointerException e) {
			return true;
		} catch (IllegalStateException e) {
			return true;
		}
	}
}