简单的北京奥运会倒计时 java 程序

public class Ex extends JFrame{ public Ex() { super("北京奥运会倒计时"); setBackground(Color.WHITE); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setBounds(150,150,300,300); JLabel label1 = new JLabel("距北京奥运会还有："); JLabel label2 = new JLabel(getDay()); label2.setForeground(Color.RED); label2.setFont(new Font("黑体",Font.BOLD,20)); JLabel label3 = new JLabel("天！pane.add(label1);pane.add(label2);pane.ad