java 万年历

转贴从：http://www.blogjava.net/soddabao/archive/2006/12/31/91098.html

  Calendar   c1   =   Calendar.getInstance();  
c1.set(yearCount,monthCount-1,1);  
   
Calendar   c2   =   Calendar.getInstance();  
c2.set(yearCount,monthCount,1);  
   
long   c2s   =   c2.getTimeInMillis();  
long   c1s   =   c1.getTimeInMillis();  
long   day   =   1* 24* 60*60*1000;     
long   days  =  (c2s-c1s)/day;  

主类：MainFrame
package clock;

/** *//**
 * MainFrame.java
 * Summary 万年历主类
 * Created on
 * @author
 * remark 如有改动请发一份代码给我，邮箱[e-mail]
 */

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Date;
import java.util.Calendar;

import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;


class MainFrame extends JFrame {
    /** *//**
     * 
     */
    private static final long serialVersionUID = 1L;
    JPanel panel = new JPanel(new BorderLayout());
    JPanel panel1 = new JPanel();
    JPanel panel2 = new JPanel(new GridLayout(7, 7));
    JPanel panel3 = new JPanel();
    JLabel[] label = new JLabel[49];
    JLabel y_label = new JLabel("年份");
    JLabel m_label = new JLabel("月份");
    JComboBox com1 = new JComboBox();
    JComboBox com2 = new JComboBox();
    int re_year, re_month;
    int x_size, y_size;
    String year_num;
    Calendar now = Calendar.getInstance(); // 实例化Calendar

    MainFrame() {
        super("万年历");
        setSize(300, 350);
        x_size = (int) (Toolkit.getDefaultToolkit().getScreenSize().getWidth());
        y_size = (int) (Toolkit.getDefaultToolkit().getScreenSize().getHeight());
        setLocation((x_size - 300) / 2, (y_size - 350) / 2);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        panel1.add(y_label);
        panel1.add(com1);
        panel1.add(m_label);
        panel1.add(com2);
        for (int i = 0; i < 49; i++) {
            label[i] = new JLabel("", JLabel.CENTER);// 将显示的字符设置为居中
            panel2.add(label[i]);
        }
        panel3.add(new Clock(this));
        panel.add(panel1, BorderLayout.NORTH);
        panel.add(panel2, BorderLayout.CENTER);
        panel.add(panel3, BorderLayout.SOUTH);
        panel.setBackground(Color.white);
        panel1.setBackground(Color.white);
        panel2.setBackground(Color.white);
        panel3.setBackground(Color.white);
        Init();
        com1.addActionListener(new ClockAction());
        com2.addActionListener(new ClockAction());

        setContentPane(panel);
        setVisible(true);
        setResizable(false);
    }

    class ClockAction implements ActionListener {
        public void actionPerformed(ActionEvent arg0) {
            int c_year, c_month, c_week;
            c_year = Integer.parseInt(com1.getSelectedItem().toString()); // 得到当前所选年份
            c_month = Integer.parseInt(com2.getSelectedItem().toString()) - 1; // 得到当前月份，并减1,计算机中的月为0－11
            c_week = use(c_year, c_month); // 调用函数use，得到星期几
            Resetday(c_week, c_year, c_month); // 调用函数Resetday
        }
    }
    
    public void Init() {
        int year, month_num, first_day_num;
        String log[] = { "日", "一", "二", "三", "四", "五", "六" };
        for (int i = 0; i < 7; i++) {
            label[i].setText(log[i]);
        }
        for (int i = 0; i < 49; i = i + 7) {
            label[i].setForeground(Color.red); // 将星期日的日期设置为红色
        }
        for (int i = 6; i < 49; i = i + 7) {
            label[i].setForeground(Color.green);// 将星期六的日期设置为绿色
        }
        for (int i = 1; i < 10000; i++) {
            com1.addItem("" + i);
        }
        for (int i = 1; i < 13; i++) {
            com2.addItem("" + i);
        }
        month_num = (int) (now.get(Calendar.MONTH)); // 得到当前时间的月份
        year = (int) (now.get(Calendar.YEAR)); // 得到当前时间的年份
        com1.setSelectedIndex(year - 1); // 设置下拉列表显示为当前年
        com2.setSelectedIndex(month_num); // 设置下拉列表显示为当前月
        first_day_num = use(year, month_num);
        Resetday(first_day_num, year, month_num);
    }

    public int use(int reyear, int remonth) {
        int week_num;
        now.set(reyear, remonth, 1); // 设置时间为所要查询的年月的第一天
        week_num = (int) (now.get(Calendar.DAY_OF_WEEK));// 得到第一天的星期
        return week_num;
    }

    @SuppressWarnings("deprecation")
    public void Resetday(int week_log, int year_log, int month_log) {
        int month_day_score; // 存储月份的天数
        int count;
        month_day_score = 0;
        count = 1;

        Date date = new Date(year_log, month_log + 1, 1); // now
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        cal.add(Calendar.MONTH, -1); // 前个月
        month_day_score = cal.getActualMaximum(Calendar.DAY_OF_MONTH);// 最后一天

        for (int i = 7; i < 49; i++) { // 初始化标签
            label[i].setText("");
        }
        week_log = week_log + 6; // 将星期数加6，使显示正确
        month_day_score = month_day_score + week_log;
        for (int i = week_log; i < month_day_score; i++, count++) {
            label[i].setText(count + "");
        }
    }

    public static void main(String[] args) {
        JFrame.setDefaultLookAndFeelDecorated(true);
        new MainFrame();
    }
}

显示时间的类：Clock
package clock;

/** *//**
 * Clock.java
 * Summary 数字时间显示
 * Created on
 * @author
 * remark 
 */

import java.awt.Canvas;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.text.SimpleDateFormat;
import java.util.Calendar;
class Clock extends Canvas implements Runnable{
    /** *//**
     * 
     */
    private static final long serialVersionUID = 3660124045489727166L;
    MainFrame mf;
    Thread t;
    String time;
    public Clock(MainFrame mf){
    this.mf=mf;
    setSize(280,40);
    setBackground(Color.white);
    t=new Thread(this);                //实例化线程
    t.start();                        //调用线程
    }
    public void run(){
    while(true){
    try{
    Thread.sleep(1000);                    //休眠1秒钟
    }catch(InterruptedException e){
    System.out.println("异常");
    }
    this.repaint(100);
    }
    }
    public void paint(Graphics g){
    Font f=new Font("宋体",Font.BOLD,16);
    SimpleDateFormat SDF=new SimpleDateFormat("yyyy'年'MM'月'dd'日'HH:mm:ss");//格式化时间显示类型
    Calendar now=Calendar.getInstance();
    time=SDF.format(now.getTime());        //得到当前日期和时间
    g.setFont(f);
    g.setColor(Color.orange);
    g.drawString(time,45,25);
    }
}