电子时钟java写的

package com.lw;
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.Calendar;
import java.util.GregorianCalendar;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
import javax.swing.UIManager;
import javax.swing.border.EmptyBorder;
public class DigitalClock extends JFrame {
/**
*
*/
private static final long serialV ersionUID = 4962111797317773666L;
private JPanel contentPane;
private JLabel label;
/**
* Launch the application.
*/
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
} catch (Throwable e) {
e.printStackTrace();
}
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
DigitalClock frame = new DigitalClock();
frame.setV isible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public DigitalClock() {
addWindowListener(new WindowAdapter() {
@Override
public void windowActivated(WindowEvent e) {
do_this_windowActivated(e);
}
});
setTitle("\u6570\u5B57\u65F6\u949F");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 200, 100);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);
label = new JLabel("New label");
label.setFont(new Font("微软雅黑", Font.BOLD, 20));
label.setHorizontalAlignment(SwingConstants.CENTER);
contentPane.add(label, BorderLayout.CENTER);
}
private String format(int number) {
return number < 10 ? "0" + number : "" + number;// 如果数字小于10就在其前面加0补齐
}
private String getTime() {
Calendar calendar = new GregorianCalendar();
int hour = calendar.get(Calendar.HOUR_OF_DAY); // 获得当前小时
int minute = calendar.get(Calendar.MINUTE); // 获得当前分钟
int second = calendar.get(Calendar.SECOND); // 获得当前秒
return format(hour) + ":" + format(minute) + ":" + format(second);// 返回格式化的字符串
}
protected void do_this_windowActivated(WindowEvent e) {
new Thread() {
public void run() {
while (true) {// 让时钟一直处于更新状态
label.setText(getTime()); // 更新时钟
try {
Thread.sleep(1000); // 休眠一秒钟
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
}.start();
}
}。