java时钟代码 来自《计算机图形学 应用Java2D和3D》

package chapter4; import java.awt.*; import java.awt.geom.*; import java.awt.event.*; import java.util.Calendar; import javax.swing.*; public class Clock2D extends JApplet { public static void main(String s[]) { JFrame frame = new JFrame(); frame.setTitle("Clock"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JApplet applet = new Clock2D(); applet.init(); frame.getContentPane().add(applet); frame.pack(); frame.setVisible(true); } public void init() { JPanel panel = new ClockPanel(); getContentPane().add(panel); } } class ClockPanel extends JPanel implements ActionListener{ AffineTransform rotH = new AffineTransform(); AffineTransform rotM = new AffineTransform(); AffineTransform rotS = new AffineTransform(); public ClockPanel() { setPreferredSize(new Dimension(640, 480)); setBackground(Color.white); Timer timer = new Timer(500, this); timer.start(); } public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2 = (Graphics2D)g; g2.translate(320,240); // clock face Paint paint = new GradientPaint(-150,-150,Color.white,150,150,Color.gray); g2.setPaint(paint); g2.fillOval(-190, -190, 380, 380); g2.setColor(Color.gray); g2.drawString("Java 2D", -20, 80); Stroke stroke = new BasicStroke(3); g2.setStroke(stroke); g2.drawOval(-190, -190, 380, 380); for (int i = 0; i < 12; i++) { g2.rotate(2*Math.PI/12); g2.fill3DRect(-3, -180, 6, 30, true); } // clock hands Shape hour = new Line2D.Double(0, 0, 0, -80); hour = rotH.createTransformedShape(hour); Shape minute = new Line2D.Double(0, 0, 0, -120); minute = rotM.createTransformedShape(minute); Shape second = new Line2D.Double(0, 0, 0, -120); second = rotS.createTransformedShape(second); g2.setColor(Color.black); g2.setStroke(new BasicStroke(5, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND)); g2.draw(hour); g2.draw(minute); g2.setStroke(new BasicStroke(2)); g2.draw(second); } public void actionPerformed(ActionEvent e) { int hour = Calendar.getInstance().get(Calendar.HOUR); int min = Calendar.getInstance().get(Calendar.MINUTE); int sec = Calendar.getInstance().get(Calendar.SECOND); rotH.setToRotation(Math.PI * (hour+min/60.0)/6.0); rotM.setToRotation(Math.PI * min /30.0); rotS.setToRotation(Math.PI * sec /30.0); repaint(); } }