int week=n;
   Date mDate=null;
   SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
   try{
       mDate=sdf.parse("2010-02-01");
   }catch(java.text.ParseException pe){}
  
   Calendar cld=Calendar.getInstance();
   cld.setFirstDayOfWeek(Calendar.MONDAY);
   cld.setTime(mDate);
   int i=cld.get(Calendar.WEEK_OF_MONTH);
   System.out.println("this is the "+i+" week!");
  
   DateFormat dateFormat =
       DateFormat.getDateInstance(DateFormat.FULL);
  GregorianCalendar cal = new GregorianCalendar();
  cal.setTime(mDate);
  System.out.println("System Date: " +
  dateFormat.format(cal.getTime()));

cal.set(GregorianCalendar.DAY_OF_WEEK,
   GregorianCalendar.MONDAY);
   System.out.println("After Setting Day of Week to Monday: " +
dateFormat.format(cal.getTime()));

cal.add(GregorianCalendar.DAY_OF_MONTH, 7*(week-1));
System.out.println("第n周的星期一是"+dateFormat.format(cal.getTime()));
cal.add(GregorianCalendar.DAY_OF_MONTH, 6);
System.out.println("第n周的星期日是"+dateFormat.format(cal.getTime()));