java时间戳转换

import java.text.SimpleDateFormat;  
import java.util.Calendar;  
import java.util.Date;  

public class DateUtils {  

        /** 
         * 返回unix时间戳 (1970年至今的秒数) 
         * @return 
         */  
        public static long getUnixStamp(){  
                return System.currentTimeMillis()/1000;  
        }  

        /** 
         * 得到昨天的日期 
         * @return 
         */  
        public static String getYestoryDate() {  
                Calendar calendar = Calendar.getInstance();    
                calendar.add(Calendar.DATE,-1);  
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");  
                String yestoday = sdf.format(calendar.getTime());  
                return yestoday;  
        }  

        /** 
         * 得到今天的日期 
         * @return 
         */  
        public static  String getTodayDate(){  
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");  
                String date = sdf.format(new Date());  
                return date;  
        }  

        /** 
         * 时间戳转化为时间格式 
         * @param timeStamp 
         * @return 
         */  
        public static String timeStampToStr(long timeStamp) {  
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
                String date = sdf.format(timeStamp * 1000);  
                return date;  
        }  

        /** 
         * 得到日期   yyyy-MM-dd 
         * @param timeStamp  时间戳 
         * @return 
         */  
        public static String formatDate(long timeStamp) {     
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");  
                String date = sdf.format(timeStamp*1000);  
                return date;  
        }  

        /** 
         * 得到时间  HH:mm:ss 
         * @param timeStamp   时间戳 
         * @return 
         */  
        public static String getTime(long timeStamp) {    
                String time = null;  
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
                String date = sdf.format(timeStamp * 1000);  
                String[] split = date.split("\\s");  
                if ( split.length > 1 ){  
                        time = split[1];  
                }  
                return time;  
        }  

        /** 
         * 将一个时间戳转换成提示性时间字符串，如刚刚，1秒前 
         *  
         * @param timeStamp 
         * @return 
         */  
        public static String convertTimeToFormat(long timeStamp) {  
                long curTime =System.currentTimeMillis() / (long) 1000 ;  
                long time = curTime - timeStamp;  

                if (time < 60 && time >= 0) {  
                        return "刚刚";  
                } else if (time >= 60 && time < 3600) {  
                        return time / 60 + "分钟前";  
                } else if (time >= 3600 && time < 3600 * 24) {  
                        return time / 3600 + "小时前";  
                } else if (time >= 3600 * 24 && time < 3600 * 24 * 30) {  
                        return time / 3600 / 24 + "天前";  
                } else if (time >= 3600 * 24 * 30 && time < 3600 * 24 * 30 * 12) {  
                        return time / 3600 / 24 / 30 + "个月前";  
                } else if (time >= 3600 * 24 * 30 * 12) {  
                        return time / 3600 / 24 / 30 / 12 + "年前";  
                } else {  
                        return "刚刚";  
                }  
        }  

        /** 
         * 将一个时间戳转换成提示性时间字符串，(多少分钟) 
         *  
         * @param timeStamp 
         * @return 
         */  
        public static String timeStampToFormat(long timeStamp) {  
                long curTime =System.currentTimeMillis() / (long) 1000 ;  
                long time = curTime - timeStamp;  
                return time/60 + "";  
        }  

}