通过Graphics对象来实现动画效果

package com.zuidaima.animate;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Insets;
import java.util.Timer;
import java.util.TimerTask;

import javax.swing.JFrame;

public class Animate extends JFrame {

	private static int DELAY = 100;

	Insets insets;

	Color colors[] = { Color.RED, Color.ORANGE, Color.YELLOW, Color.GREEN,
			Color.BLUE, Color.MAGENTA };

	public void paint(Graphics g) {
		super.paint(g);
		if (insets == null) {
			insets = getInsets();
		}
		// Calculate each time in case of resize
		int x = insets.left;
		int y = insets.top;
		int width = getWidth() - insets.left - insets.right;
		int height = getHeight() - insets.top - insets.bottom;
		int start = 0;
		int steps = colors.length;
		int stepSize = 360 / steps;
		synchronized (colors) {
			for (int i = 0; i < steps; i++) {
				g.setColor(colors[i]);
				g.fillArc(x, y, width, height, start, stepSize);
				start += stepSize;
			}
		}
	}

	public void go() {
		TimerTask task = new TimerTask() {
			public void run() {
				Color c = colors[0];
				synchronized (colors) {
					System.arraycopy(colors, 1, colors, 0, colors.length - 1);
					colors[colors.length - 1] = c;
				}
				repaint();
			}
		};
		Timer timer = new Timer();
		timer.schedule(task, 0, DELAY);
	}

	public static void main(String args[]) {
		Animate f = new Animate();
		f.setSize(200, 200);
		f.show();
		f.go();
	}
}