java学期周数的计算，求算法

输入某学期第一周周一的日期（年、月、日），在输入要查询的日期，点击计算按钮，显示出查询日期是第几周周几。例如，输入的第一周周一的时间为2010年8月30日，再输入2010-12-2，则计算出2010-12-2为第14周周四。
界面要求：用图形界面实现。
PS:用户图形界面我已经写好了 只要求各位大神们给我个算法代码就可以了
import java.awt.*;
import java.awt.event.*;
public class jisuanJFrame extends Frame implements ActionListener
{
private TextField text_char;
private Button button_char;
public jisuanJFrame()
{
super("学周数的计算");
this.setBounds(280,100,100,150);
this.setBackground(java.awt.Color.lightGray);
this.setLayout(new java.awt.FlowLayout(FlowLayout.LEFT));
this.add(new Label("日期"));
this.add(new TextField("2010年8月30日"));
this.add(new TextField(20));
this.add(new Button("计算"));
this.addWindowListener(new WinClose());
this.setVisible(true);
}
public static void main(String arg[])
{
new jisuanJFrame();
}
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub

}
}
class WinClose implements WindowListener
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}

public void windowOpened(WindowEvent e){}
public void windowActivated(WindowEvent e){}
public void windowDeactivated(WindowEvent e){}
public void windowClosed(WindowEvent e){}
public void windowIconified(WindowEvent e){}
public void windowDeiconified(WindowEvent e){}
}

//一个简单的日期计算程序

import java.util.*;
import java.text.*;

public class DateCalculator
{
Date standardDate;
DateFormat mf = new SimpleDateFormat( "yyyy.MM.dd ");
Calendar cal = Calendar.getInstance();
Calendar cal_temp = Calendar.getInstance();

public DateCalculator()
{
try{
standardDate = mf.parse( "2000.01.01 ");
}
catch(ParseException ep){
ep.printStackTrace();
}
}

//设置基本日期,使用 "yyyy.MM.dd "格式的字符串
public boolean setStandardDate(String str)
{
Date date;
try{
date = mf.parse(str);
}
catch(ParseException ep){
ep.printStackTrace();
return false;
}

standardDate = date;
return true;
}

public boolean setStandardDate(Date date)
{
standardDate = getOnlyDate(date);
return true;
}

//year 为年数
//month 为月份,以 0 开始,与系统的不同,取值 0-11
//为的是与Java的内部使用兼容
//day 为日期天数
public boolean setStandardDate(int year,int month,int day)
{
cal.clear();
cal.set(year,month,day);
standardDate = cal.getTime();
return true;
}

public boolean setStandardDate(long time)
{
standardDate = getOnlyDate(time);
return true;
}

public Date getStandardDate()
{
return standardDate;
}

//取得一个只有日期,不含有时间的日期,也就是时间是 0时 0分 0秒.
public Date getOnlyDate(Date date)
{
cal.setTime(date);
cal_temp.clear();
cal_temp.set(cal.get(Calendar.YEAR),cal.get(Calendar.MONTH),cal.get(Calendar.DAY_OF_MONTH));
return cal_temp.getTime();
}

public Date getOnlyDate(long time)
{
cal.setTimeInMillis(time);
cal_temp.clear();
cal_temp.set(cal.get(Calendar.YEAR),cal.get(Calendar.MONTH),cal.get(Calendar.DAY_OF_MONTH));
return cal_temp.getTime();
}

//使用一个字符串取得一个日期,样式 "yyyy.MM.dd "格式的字符串
public Date getDate(String str)
{
Date date;
try{
date = mf.parse(str);
}
catch(ParseException ep){
ep.printStackTrace();
return getOnlyDate(new Date());
}
return date;
}

//使用输入的日期减去标准日期,得到相差的天数
public int sub(Date date)
{
long temp = date.getTime()-standardDate.getTime();
if(temp> 0)
{
return (int)(temp/(24*60*60*1000));
}
else
{
return (int)(temp/(24*60*60*1000))-1;
}
}

//使用 b_date - j_date 得到相差的天数
public int sub(Date b_date , Date j_date)
{
Date date = getOnlyDate(j_date);
long temp = b_date.getTime()-date.getTime();
if(temp> 0)
{
return (int)(temp/(24*60*60*1000));
}
else
{
return (int)(temp/(24*60*60*1000))-1;
}
}

//得到标准日期减去几天后的日期
public Date add(int day)
{
cal.setTime(standardDate);
cal.add(Calendar.DATE,day);
return cal.getTime();
}

//得到 date 减去几天后的日期
public Date add(Date date , int day)
{
cal.setTime(date);
cal.add(Calendar.DATE,day);
return cal.getTime();
}

public static void main(String args[])
{
DateCalculator temp = new DateCalculator();
Date d = temp.getDate( "2003.01.01 ");
int i = temp.sub(new Date(),d);
System.out.println (i);
}
}

import java.awt.*; import java.awt.event.*; public class calcappdemo extends frame{ private textfield t_result; private panel p_main; //主面板 private panel p_num; //数字面板 private panel p_oper; //操作符面板 private panel p_show; //显示面板 private button b_num[]; //数字按钮 private button b_oper[]; //操作符面板 public calcappdemo(string title){ settitle(title); t_result = new textfield("0.0", 21); p_main = new panel(); p_num = new panel(); p_oper = new panel(); p_show = new panel(); p_main.setlayout(new borderlayout()); p_num.setlayout(new gridlayout(4, 3, 1, 1)); p_oper.setlayout(new gridlayout(4, 2, 1, 1)); b_num = new button[12]; for(int i=0; i<9; i++) { b_num = new button(new integer(i+1).tostring()); } b_num[9] = new button("0"); b_num[10] = new button("cls"); b_num[11] = new button("."); for(int i=0; i<12; i++) { p_num.add(b_num); } b_oper = new button[8]; b_oper[0] = new button("+"); b_oper[1] = new button("-"); b_oper[2] = new button("*"); b_oper[3] = new button("/"); b_oper[4] = new button("pow"); b_oper[5] = new button("sqrt"); b_oper[6] = new button("+/-"); b_oper[7] = new button("="); for(int i=0; i<8; i++) // { p_oper.add(b_oper); } t_result.seteditable(false); p_show.add(t_result, borderlayout.north); p_main.add(p_show, borderlayout.north); p_main.add(p_num, borderlayout.west); p_main.add(p_oper, borderlayout.east); this.add(p_main, borderlayout.center); setsize(400, 400); setresizable(false); pack(); this.addwindowlistener(new windowadapter(){ public void windowclosing(windowevent e) { system.exit(0); } }); buttonlistener b1 = new buttonlistener(); for(int i=0; i<12; i++) { b_num.addactionlistener(b1); } for(int i=0; i<8; i++) { b_oper.addactionlistener(b1); } } class buttonlistener implements actionlistener { private string lastop; //存储上一此操作符 private string strval; //存储数字对应的字符串 private double total; //总数 private double number; //存储新输入的数 private boolean firsttime; //判断是否第一次按下的是操作符按钮 private boolean operatorpressed;//判断是否已经按过操作符按钮 buttonlistener() { firsttime = true; strval = ""; } //事件处理器 public void actionperformed(actionevent e) { string s = ((button)e.getsource()).getlabel().trim(); if(character.isdigit(s.charat(0))) {//判断是操作数还是操作符 handlenumber(s); } else { calculate(s); } } //判断是一元操作符还是二元操作符，并根据操作符类型做计算 void calculate(string op) { operatorpressed = true; if(firsttime&&! isunary(op)) { total = getnumberondisplay(); firsttime = false; } if(isunary(op)) { handleunaryop(op); } else if(lastop != null) { handlebinaryop(lastop); } if(! isunary(op)) { lastop = op; } } //判断是否一元操作符 boolean isunary(string s) { return s.equals("=") ||s.equals("cls")||s.equals("sqrt") ||s.equals("+/-")||s.equals("."); } //处理一元操作符 void handleunaryop(string op) { if(op.equals("+/-")) {// number = negate(getnumberondisplay() + ""); t_result.settext(""); t_result.settext(number + ""); return; }else if(op.equals(".")) { handledecpoint(); return; }else if(op.equals("sqrt")) { number = math.sqrt(getnumberondisplay()); t_result.settext(""); t_result.settext(number + ""); return; }else if(op.equals("=")) {// if(lastop!= null && !isunary(lastop)) { handlebinaryop(lastop); } lastop = null; firsttime = true; return; }else { clear(); } } //处理二元运算符 void handlebinaryop(string op) { if(op.equals("+")) { total +=number; }else if(op.equals("-")) { total -=number; }else if(op.equals("*")) { total *=number; }else if(op.equals("/")) { try { total /=number; }catch(arithmeticexception ae){} }else if(op.equals("pow")) total = math.pow(total, number); //t_result.settext(""); lastop = null; // strval = ""; number = 0; t_result.settext(total + ""); } //该方法用于处理数字按钮 void handlenumber(string s) { if(!operatorpressed) { strval += s; }else { operatorpressed = false; strval = s; } // number = new double(strval).doublevalue(); t_result.settext(""); t_result.settext(strval); } //该方法用于按下"."按钮 void handledecpoint() { operatorpressed = false; // if(strval.indexof(".")<0) { strval += "."; } t_result.settext(""); t_result.settext(strval); } //该方法用于将一个数求反 double negate(string s) { operatorpressed = false; //如果是一个整数，去掉小数点后面的0 if(number == (int)number) { s = s.substring(0,s.indexof(".")); } //如果无"-"增加在该数的前面 if(s.indexof("-")<0) { strval = "-" + s; } else { strval = s.substring(1); } return new double(strval).doublevalue(); } //将显示框中的值转换成double double getnumberondisplay() { return new double(t_result.gettext()).doublevalue(); } //清除屏幕并设置所有的标识 void clear() { firsttime = true; lastop = null; strval = ""; total = 0; number = 0; t_result.settext("0"); } } public static void main(string[] args) { calcappdemo c = new calcappdemo("简单的计算器程序"); c.setvisible(true); } }