java将日期转换成周几

   Date date=new Date();

   SimpleDateFormat dateFm = new SimpleDateFormat("EEEE");

   dateFm.format(date);

或

   String[] weekDays = {"星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六"};
   Calendar calendar = Calendar.getInstance();
   calendar.setTime(dt);

   int i = calendar.get(Calendar.DAY_OF_WEEK) - 1;
   if (i < 0){
     i = 0;
　　}
   return weekDays[i];