由于最近要搞毕业设计，正好我的论文就是Java这块的。我就将自己用Java做的万年历贴到我的博客。希望能给需要的人一点帮助。

/**
 * MainFrame.java
 * Summary 万年历主类
 */

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.text.*;
import java.util.*;
class Clock extends Canvas implements Runnable{
    MainFrame mf;
    Thread t;
    String time;
    Clock(MainFrame mf){
    this.mf=mf;
    setSize(400,40);
    setBackground(Color.white);
    t=new Thread(this);                //实例化线程
    t.start();                        //调用线程   
    }
    public void run(){
    while(true){
    try{
    t.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.red);
    g.drawString(time,100,25);
    }
}

class MainFrame extends JFrame{
    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 年份=new JLabel("年份");
    JLabel 月份=new JLabel("月份");
    JComboBox com1=new JComboBox();    //下拉窗口
    JComboBox com2=new JComboBox();
    JButton 查看=new JButton("查看");
    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(年份);
        panel1.add(com1);
        panel1.add(月份);
        panel1.add(com2);
        panel1.add(查看);
        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.yellow);
        panel2.setBackground(Color.white);
        panel3.setBackground(Color.blue);
        Init();
        查看.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e){
                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
            }});
        setContentPane(panel);
        setVisible(true);
        setResizable(false);
    }
    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.red);//将星期六的日期设置为红色
    }
    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;
    }
    public void Resetday(int week_log,int year_log,int month_log){
        int month_score_log;    //判断是否是闰年的标记
        int month_day_score;    //存储月份的天数
        int count;
        month_score_log=0;
        month_day_score=0;
        count=1;
        if(year_log%4==0&&year_log%100!=0||year_log%400==0){//判断是否为闰年
            month_score_log=1;
        }
    month_log=month_log+1;    //将传来的月份数加1
    switch(month_log){
        case 1:
        case 3:
        case 5:
        case 7:
        case 8:
        case 10:
        case 12:
        month_day_score=31;
        break;
        case 4:
        case 6:
        case 9:
        case 11:
        month_day_score=30;
        break;
        case 2:
        if(month_score_log==1){
        month_day_score=29;   
        }
        else{
        month_day_score=28;
        }
        break;
        }
        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);
        MainFrame start=new MainFrame();
    }    
}