Java时间处理（xx年前，xx天前，xx小时前）

	 public static Date getDateByString(String time) {
	        Date date = null;
	        if(time == null) {
	        	return date;
	        }
	        
	        String pattern = "yyyy-MM-dd HH:mm:ss";
	        SimpleDateFormat format = new SimpleDateFormat(pattern);
	        try {
	            date = format.parse(time);
	        } catch (ParseException e) {
	            e.printStackTrace();
	        }
	        return date;
	    }
	      
	    public static String getShortTime(String time) {
	        String shortString = null;
	        long now = Calendar.getInstance().getTimeInMillis();
	        Date date = getDateByString(time);
	        if(date == null) {
	        	return shortString;
	        }
	        long delTime = (now - date.getTime()) / 1000;
	        if (delTime > 365 * 24 * 60 * 60) {
	        	shortString = (int) (delTime / (365 * 24 * 60 * 60)) + "年前";
	        } else if (delTime > 24 * 60 * 60) {
	        	shortString = (int) (delTime / (24 * 60 * 60)) + "天前";
	        } else if (delTime > 60 * 60) {
	        	shortString = (int) (delTime / (60 * 60)) + "小时前";
	        } else if (delTime > 60) {
	        	shortString = (int) (delTime / (60)) + "分前";
	        } else if (delTime > 1) {
	        	shortString = delTime + "秒前";
	        } else {
	        	shortString = "1秒前";
	        }
	        return shortString;
	    }

       String time = "2012-02-28 10:40:55";
       System.out.println(getShortTime(time));