Android获取本周本月本年的第一天和最后一天

获取本周的第一天和最后一天：

SimpleDateFormat dateFormater = new SimpleDateFormat(
						"yyyy-MM-dd");
				Calendar cal = Calendar.getInstance();
				cal.set(Calendar.DAY_OF_WEEK, 1);
				cal.getTime();
				start_time.setText(dateFormater.format(cal.getTime()) + "");

				cal.set(Calendar.DAY_OF_WEEK,
						cal.getActualMaximum(Calendar.DAY_OF_WEEK));
				end_time.setText(dateFormater.format(cal.getTime()));SimpleDateFormat dateFormat