日期处理

	/**
	 * 去年今天
	 * @return
	 */
	  public static String getNowOfLastYear() {
	        // Date Format will be display
	        SimpleDateFormat aSimpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
	        GregorianCalendar aGregorianCalendar = new GregorianCalendar();
	        // Get last month GregorianCalendar object
	        aGregorianCalendar.set(Calendar.YEAR, aGregorianCalendar
	                .get(Calendar.YEAR) - 1);
	        // Format the date to get year and month
	        String currentYearAndMonth = aSimpleDateFormat
	                .format(aGregorianCalendar.getTime());
	        return currentYearAndMonth;
	    }
	  /**
	 * 上个月今天
	 * @return
	 */
	  public static String getMonthDate() {
	        // Date Format will be display
	        SimpleDateFormat aSimpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
	        GregorianCalendar aGregorianCalendar = new GregorianCalendar();
	        // Get last month GregorianCalendar object
	        aGregorianCalendar.set(Calendar.MONTH, aGregorianCalendar
	                .get(Calendar.MONTH) - 1);
	        // Format the date to get year and month
	        String currentYearAndMonth = aSimpleDateFormat
	                .format(aGregorianCalendar.getTime());
	        return currentYearAndMonth;
	    }