Java时间处理（xx天前、xx年前）

不用我告诉你这个功能多么有用吧。。。。网上看到的，不敢独享

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
  
/**
 * 
 * @author Robot
 *
 */
public class test {
      
    public static Date getDateByString(String time) {
        Date date = null;
        if(time == null) return date;
        String date_format = "yyyy-MM-dd HH:mm:ss";
        SimpleDateFormat format = new SimpleDateFormat(date_format);
        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;
    }
      
    public static void main(String\[\] args) {
        String time = "2012-02-28 10:40:55";
        System.out.println(getShortTime(time));
    }
      
}