Question

在java中，如何在标签里每秒显示一下当前系统时间

Answer 1

public class MyDesktopPane extends JFrame implements ActionListener {

final static JDesktopPane desktopPane = new JDesktopPane();

public MyDesktopPane() {
super("MyDesktopPane.java:DesktopPane测试");
JMenuBar menuBar = new JMenuBar();
JMenu menu = new JMenu("新增窗口");
JMenuItem menultem = new JMenuItem("内部框架窗口");
menu.add(menultem);
menuBar.add(menu);
setJMenuBar(menuBar);
getContentPane().add(desktopPane);
menultem.addActionListener(this);
setSize(350, 200);
setVisible(true);
}

public void actionPerformed(ActionEvent e) {
JInternalFrame inFrame = new JInternalFrame("内部框架（圆环）", true, true, true, true);
Container c = inFrame.getContentPane();
CirclePanel circlePanel = new CirclePanel();
JLabel label = new JLabel("圆环");
c.add(circlePanel, BorderLayout.CENTER);
c.add(label, BorderLayout.WEST);
int w = circlePanel.getImageWidthHeight().width + 150;
int h = circlePanel.getImageWidthHeight().height + 50;
inFrame.setSize(w, h);
inFrame.reshape(100, 50, w, h);
inFrame.setOpaque(true);
desktopPane.add(inFrame);
inFrame.setVisible(true);
}

public static void main(String args[]) {
MyDesktopPane app = new MyDesktopPane();
app.addWindowListener(new MyWindowListener());
}
}

class CirclePanel extends JPanel {

private ImageIcon imglcon;

public CirclePanel() {
try {
imglcon = new ImageIcon(new URL(""));
} catch (MalformedURLException ex) {
Logger.getLogger(CirclePanel.class.getName()).log(Level.SEVERE, null, ex);
}
}

public void paint(Graphics g) {
g.drawImage(imglcon.getImage(), 0, 0, this);
}

public Dimension getImageWidthHeight() {
return new Dimension(imglcon.getIconWidth(), imglcon.getIconHeight());
}
}

class MyWindowListener extends WindowAdapter {

public void windowClosing(WindowEvent e) {
System.exit(1);
}
}

Answer 2

我建议是使用js代码来实现系统时间的实现，而不需要系统每秒从服务器返回一个值来客户端上。

Answer 3

js中有关于显示时间的对象Date， 如：var date=new Date(); date.get**（）； 自己查一下

Answer 4

建议用线程试试！
希望对你有帮助……