JAVA计时器的JAVA代码

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

public class Clock extends Applet {
private final Panel pnlTop = new Panel();
private final Panel pnlBot = new Panel();
private final Label lblDate = new Label();
private final Label lblTime = new Label();
private final Label lblWatch = new Label();
private final Button btnGo = new Button("开始");
private final Button btnReset = new Button("重置");
private final Label lblSplit = new Label();
private final Button btnSplit = new Button("定点");
private final Button btnSplitReset = new Button("定点重置");
private final Button btnLapAdd = new Button("冲线");
private final Button btnLapReset = new Button("冲线重置");
private final java.awt.List lstLaps = new java.awt.List();
private final UpdateClockThread ucThread = new UpdateClockThread();
private final StopwatchThread swThread = new StopwatchThread();

private class btnGoListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
if ((btnGo.getLabel().equals("开始")) ||
(btnGo.getLabel().equals("继续"))) {
// Start the clock!
swThread.go();
btnGo.setLabel("停止");
btnGo.setBackground(Color.red);
} else if (btnGo.getLabel().equals("停止")) {
// Stop the clock!
swThread.noGo();
btnGo.setLabel("继续");
btnGo.setBackground(Color.green);
}
}
}

private class btnResetListener implements ActionListener {
/** Actually run when the button gets clicked.
*@param e The event
*/
public void actionPerformed(ActionEvent e) {
swThread.reset();
btnGo.setLabel("开始");
btnGo.setBackground(Color.green);
}
}

/** Listens to the Split button.
* @version CS2136 - Term D'00 - Assignment 5
* @author Peter Cooper Jr.
*/
private class btnSplitListener implements ActionListener {
/** Actually run when the button gets clicked.
*@param e The event
*/
public void actionPerformed(ActionEvent e) {
lblSplit.setText(lblWatch.getText());
}
}

/** Listens to the Split Reset button.
* @version CS2136 - Term D'00 - Assignment 5
* @author Peter Cooper Jr.
*/
private class btnSplitResetListener implements ActionListener {
/** Actually run when the button gets clicked.
*@param e The event
*/
public void actionPerformed(ActionEvent e) {
lblSplit.setText("");
}
}

/** Listens to the Lap Add button.
* @version CS2136 - Term D'00 - Assignment 5
* @author Peter Cooper Jr.
*/
private class btnLapAddListener implements ActionListener {
/** Actually run when the button gets clicked.
*@param e The event
*/
public void actionPerformed(ActionEvent e) {
swThread.addLap();
}
}

/** Listens to the Lap Reset button.
* @version CS2136 - Term D'00 - Assignment 5
* @author Peter Cooper Jr.
*/
private class btnLapResetListener implements ActionListener {
/** Actually run when the button gets clicked.
*@param e The event
*/
public void actionPerformed(ActionEvent e) {
swThread.resetLap();
}
}

/** A thread that updates the current date & time.
* @version CS2136 - Term D'00 - Assignment 5
* @author Peter Cooper Jr.
*/
private class UpdateClockThread extends Thread {
/** The actual work of the thread.
*/
public void run() {
while (true) {
Calendar now = Calendar.getInstance();
String month = Integer.toString(now.get(Calendar.MONTH)+1);
String date = Integer.toString(now.get(Calendar.DAY_OF_MONTH));
String year = Integer.toString(now.get(Calendar.YEAR));
String hour = Integer.toString(now.get(Calendar.HOUR));
if (hour.equals("0")) hour = "12";
String minute = Integer.toString(now.get(Calendar.MINUTE));
if (minute.length() == 1) minute = "0" + minute;
String second = Integer.toString(now.get(Calendar.SECOND));
if (second.length() == 1) second = "0" + second;
String ampm = now.get(Calendar.AM_PM) == Calendar.AM
? "AM" : "PM";

lblDate.setText(month + "/" + date + "/" + year);
lblTime.setText(hour + ":" + minute + ":" + second
+ " " + ampm);
try {
sleep(500);
} catch (InterruptedException e) {}
}
}
}

private class StopwatchThread extends Thread {
/** Whether or not stopwatch is running. */
private boolean going = false;
/** Stores elapsed milliseconds of previous runs. */
private long prevElapsed = 0;
/** Stores beginning time of this run. */
private Date startDate = new Date();
/** Current lap number. */
private int lapNum = 0;
/** Elapsed time at end of last lap. */
private long lastLapTime = 0;

/** Returns elapsed time in milliseconds.
*@return The elapsed time
*/
private long elapsedTime() {
return prevElapsed +
(going ? new Date().getTime() - startDate.getTime() : 0);
}
/** Changes the number of elapsed milliseconds into a string.
*@param time Number of elapsed milliseconds
*@return The elapsed time as a string.
*/
private String msToString(long time) {
String ms， sec， min;
if (time % 10 >= 5) //round to nearest hundredth
time += 5;
ms = Long.toString(time % 1000);
while (ms.length() < 3)
ms = "0" + ms;
ms = ms.substring(0， ms.length() - 1);
time /= 1000;
sec = Long.toString(time % 60);
if (sec.length() == 1) sec = "0" + sec;
time /= 60;
min = Long.toString(time);
return min + ":" + sec + "." + ms;
}

public void go() {
startDate = new Date();
going = true;
}
public void noGo() {
prevElapsed = elapsedTime();
going = false;
}
public void reset() {
going = false;
prevElapsed = 0;
lastLapTime = 0;
}
public void addLap() {
long elapsed = elapsedTime();
lstLaps.add("冲线 " + Integer.toString(++lapNum)+ " -- " +
"用时: " + msToString(elapsed) + " -- " +
"冲线时间: " + msToString(elapsed - lastLapTime));
lastLapTime = elapsed;
}
/** Resets the lap list.
*/
public void resetLap() {
lstLaps.removeAll();
lapNum = 0;
lastLapTime = 0;
}
/** Main code of the thread.
*/
public void run() {
while (true) {
lblWatch.setText(msToString(elapsedTime()));
yield();
}
}
}

public void init() {
setLayout(new GridLayout(2，1));
setBackground(Color.lightGray);
setForeground(Color.black);
pnlTop.setLayout(new GridLayout(4，4));
pnlTop.add(new Label("日期:"));
pnlTop.add(lblDate);
pnlTop.add(new Label("时间:"));
pnlTop.add(lblTime);
pnlTop.add(new Label("计时:"));
//lblWatch.setBackground(Color.black);
lblWatch.setForeground(Color.blue);
pnlTop.add(lblWatch);
pnlTop.add(btnGo);
btnGo.setBackground(Color.green);
pnlTop.add(btnReset);
pnlTop.add(new Label("定点:"));
pnlTop.add(lblSplit);
pnlTop.add(btnSplit);
pnlTop.add(btnSplitReset);
pnlTop.add(new Label("冲线时间:"));
pnlTop.add(new Label());
pnlTop.add(btnLapAdd);
pnlTop.add(btnLapReset);
pnlBot.setLayout(new GridLayout(1，1));
pnlBot.add(lstLaps);
add(pnlTop);
add(pnlBot);
btnGo.addActionListener(new btnGoListener());
btnReset.addActionListener(new btnResetListener());
btnSplit.addActionListener(new btnSplitListener());
btnSplitReset.addActionListener(new btnSplitResetListener());
btnLapAdd.addActionListener(new btnLapAddListener());
btnLapReset.addActionListener(new btnLapResetListener());
swThread.setDaemon(true);
ucThread.setDaemon(true);
swThread.start();
ucThread.start();
}

public static void main(String[] args) {
Clock applet = new Clock();
Frame aFrame = new Frame("计时器");
aFrame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
aFrame.add(applet， BorderLayout.CENTER);
aFrame.setSize(400， 200);
applet.init();
applet.start();
aFrame.setVisible(true);
}
}

用线程实现就可以实现了