java中已知WEEK_OF_YEAR，確定當前周的週一和週日

Calendar cal = Calendar.getInstance(); cal.set(Calendar.WEEK_OF_YEAR,18);//18爲週數 Calendar cal1 = (Calendar)cal.clone(); int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK); cal.add(Calendar.DATE,cal.getActualMinimum(Calendar.DAY_OF_WEEK)-dayOfWeek); cal.add(Calendar.DATE, 1); Date d = cal.getTime(); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); System.out.println(sdf.format(d)); cal1.add(Calendar.DATE,cal1.getActualMaximum(Calendar.DAY_OF_WEEK)-dayOfWeek); cal1.add(Calendar.DATE, 1); System.out.println(sdf.format(cal1.getTime()));