GregorianCalender calender = new GregorianCalender();
calender.setTime(yourdate);
int weekday = calender.get(calender.DAY_OF_WEEK);//星期天为0
calender.setTime(yourdate);
int weekday = calender.get(calender.DAY_OF_WEEK);//星期天为0
cal.set(year,month-1,day);
int posOfWeek=cal.get(Calender.DAY_OF_WEEK);