leapyear.java

一系列java小程序

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

public class leapyear extends java.applet.Applet implements ActionListener
{
    Label        result;
    TextField   in1;
    Button       btn;
    int             year;
    boolean    leap;

    public void init()
    {   result=new Label("请先输入待判断的年份");
        in1=new TextField(5);
        btn=new Button("判断");

        add(in1);
        add(btn);
        add(result);
        btn.addActionListener(this);
    }

    public void actionPerformed(ActionEvent e)
    {
        year=Integer.parseInt(in1.getText());

        if ( year % 4 != 0 )               
            leap = false;                    
        else if ( year % 100 != 0 )   
            leap = true;
        else if ( year % 400 != 0 )
            leap = false;
        else
            leap = true;

        if ( leap == true )
            result.setText(year+"年是闰年");
        else
            result.setText(year+"年不是闰年");

        in1.setText("");
   }
}