對於Java中鐘表的開發，許多初學者很感興趣，先分析如下：
應用技術：java多線程，java圖像加載，Java雙緩沖技術
多媒體：用於指針走動，字幕顯示。
雙緩沖：用於消除圖像的閃爍。
參考代碼：
package picture;
import Java.awt.*;
import Java.awt.event.*;
import Javax.swing.*;
import Java.applet.*;
import Java.util.Date;
import Java.io.*;
import Java.awt.geom.*;
import Java.awt.Color;
import Java.awt.image.*;
public class Clock extends Applet implements MouseListener, Runnable,
ActionListener {
Image image, image1;
Toolkit tool;
JPanel panel;
Graphics gg;
int width, height, width1, height1;
Thread thread, thread2;
MediaTracker m;
double angel1 = 0, angel2 = 0;
int xsec, ysec, xsec2, ysec2;
int c = 0;
int xmin, ymin, xmin2, ymin2;
int xhou, yhou, xhou2, yhou2;
int xstr = 235, ystr = 253;
int y = ystr;
JButton button1 = new JButton();
JButton button2 = new JButton();
JButton button3 = new JButton();
JButton button4 = new JButton();
AudioClip music;
Color colorh = Color.GREEN, colorm = Color.BLACK, colors = Color.YELLOW;
String[] string = new String[5];
int kk = 0;
public void init() {
this.setLayout(new BorderLayout());
this.setBackground(Color.BLACK);
tool = getToolkit();
image = tool.getImage("image.PNG");
m = new MediaTracker(this);
m.addImage(image, 0);
try {
m.waitForID(0);
} catch (Exception e) {
System.out.println(e.getMessage());
}
width1 = image.getWidth(this);
height1 = image.getHeight(this);
width = this.WIDTH;
height = this.HEIGHT;
// music =Applet.newAudioClip(new URL("D:\\Java\\Picture\\鐘聲.wav")) ;
// music.loop();
this.addMouseListener(this);
button1.setText("時針顏色");
button1.addActionListener(this);
button2.setText("分針顏色");
button2.addActionListener(this);
button3.setText("秒針顏色");
button3.addActionListener(this);
button4.setText("選擇皮膚");
button4.addActionListener(this);
button1.setBackground(Color.BLACK);
button1.setForeground(Color.WHITE);
button2.setBackground(Color.BLACK);
button2.setForeground(Color.WHITE);
button3.setBackground(Color.BLACK);
button3.setForeground(Color.WHITE);
button4.setBackground(Color.BLACK);
button4.setForeground(Color.WHITE);
JPanel panel = new JPanel();
panel.setBackground(Color.BLACK);
panel.setLayout(new FlowLayout(FlowLayout.CENTER));
panel.add(button1);
panel.add(button2);
panel.add(button3);
panel.add(button4);
this.setLayout(new BorderLayout());
this.add(panel, BorderLayout.SOUTH);
string[0] = "時間就像海綿裡水";
string[1] = "只要擠總會有的";
string[2] = "珍惜身邊每一個人";
string[3] = "因為隨著歲月流逝，";
string[4] = "他們將......";
image1 = createImage(getWidth(), getHeight() - 35);
gg = image1.getGraphics();
}
public void start() {
if (thread == null) {
thread = new Thread(this);
thread.start();
}
if (thread2 == null) {
thread2 = new Thread(new thread2());
thread2.start();
}
}
public void paint(Graphics g) {
super.paint(g);
g.drawImage(image1, 0, 0, this);
Date date = new Date();
int hour = date.getHours();
int min = date.getMinutes();
int sec = date.getSeconds();
String m = Integer.toString(hour) + ":" + Integer.toString(min) + ":" +
Integer.toString(sec);
double ans = (Math.PI / 30) * sec;
double anm = (3.1415926535897931D / 30) * min;
double anh = ((hour + min / 60.0) * (2 * Math.PI / 12));
xsec2 = 172 + (int) (45 * Math.sin(ans));
ysec2 = 165 - (int) (45 * Math.cos(ans));
xsec = 172 - (int) (13 * Math.sin(ans));
ysec = 165 + (int) (13 * Math.cos(ans));
xmin2 = 172 + (int) (40 * Math.sin(anm));
ymin2 = 165 - (int) (40 * Math.cos(anm));
xmin = 172 - (int) (10 * Math.sin(anm));
ymin = 165 + (int) (10 * Math.cos(anm));
xhou = 172 + (int) (30 * Math.sin(anh));
yhou = 165 - (int) (30 * Math.cos(anh));
xhou2 = 172 - (int) (10 * Math.sin(anh));
yhou2 = 165 + (int) (10 * Math.cos(anh));
g.setColor(colors); //秒針
g.drawLine(xsec, ysec, xsec2, ysec2);
g.setColor(colorm); //分針
g.drawLine(xmin, ymin, xmin2, ymin2);
g.setColor(colorh); //時針
g.drawLine(xhou2, yhou2, xhou, yhou);
g.setColor(Color.RED);
g.fillOval(169, 162, 9, 9);
g.drawString(m, 150, 100);
g.setColor(Color.WHITE);
g.drawString(string[0], xstr, y);
g.drawString(string[1], xstr, y + 20);
g.drawString(string[2], xstr, y + 40);
g.drawString(string[3], xstr, y + 60);
g.drawString(string[4], xstr, y + 80);
}
public void update(Graphics g) {
paint(g);
}
public void run() {
while (true) {
try {
thread.sleep(1000);
gg.setColor(Color.WHITE);
gg.fillRect(0, 0, width, height);
gg.drawImage(image, 110, 100, width1, height1, this);
repaint();
} catch (Exception e) {
System.out.print(e.getMessage());
}
}
}
private class thread2 implements Runnable {
public void run() {
while (true) {
try {
thread2.sleep(100);
} catch (Exception e) {}
y--;
if (y <= 5) {
y = ystr;
}
repaint();
}
}
}
public void mouseClicked(MouseEvent e) {
System.out.print(e.getX());
System.out.print(e.getY());
}
public void mouseExited(MouseEvent e) {}
public void mouseEntered(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
public void fileSelect() {
JFileChooser choose = new JFileChooser();
choose.setFileSelectionMode(JFileChooser.FILES_ONLY);
choose.setCurrentDirectory(new File("."));
choose.setFileFilter(new Javax.swing.filechooser.FileFilter() {
public boolean accept(File file) {
String name = file.getName().toLowerCase();
return name.endsWith(".gif")
|| name.endsWith(".jpg")
|| name.endsWith(".jpeg")
|| file.isDirectory();
}
public String getDescription() {
return "圖片文件";
}
}
);
int result = choose.showOpenDialog(this);
String name = null;
if (result == JFileChooser.APPROVE_OPTION) {
name = choose.getSelectedFile().getAbsolutePath();
}
image = tool.getImage(name);
m.addImage(image, 0);
try {
m.waitForAll();
} catch (Exception e) {
System.out.print(e.getMessage());
}
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == button1 || e.getSource() == button2 ||
e.getSource() == button3) {
JColorChooser choose = new JColorChooser();
Color c = choose.showDialog(this, "顏色選取", Color.BLACK);
if (c == null) {
c = Color.BLACK;
}
if (e.getSource() == button1) {
colorh = c;
}
if (e.getSource() == button2) {
colorm = c;
}
if (e.getSource() == button3) {
colors = c;
}
}
if (e.getSource() == button4) {
fileSelect();
}
}
}
