更多更全的工具类，请参考github上的Blankj/AndroidUtilCode

将毫秒转换为小时：分钟：秒格式

public static String ms2HMS(int _ms){
        String HMStime;
        _ms/=1000;
        int hour=_ms/3600;
        int mint=(_ms%3600)/60;
        int sed=_ms%60;
        String hourStr=String.valueOf(hour);
        if(hour<10){
            hourStr="0"+hourStr;
        }
        String mintStr=String.valueOf(mint);
        if(mint<10){
            mintStr="0"+mintStr;
        }
        String sedStr=String.valueOf(sed);
        if(sed<10){
            sedStr="0"+sedStr;
        }
        HMStime=hourStr+":"+mintStr+":"+sedStr;
        return HMStime;
    }

将毫秒转换为标准日期格式

public static String ms2Date(long _ms){
        Date date = new Date(_ms);
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.getDefault());
        return format.format(date);
    }

    public static String ms2DateOnlyDay(long _ms){
        Date date = new Date(_ms);
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault());
        return format.format(date);
    }

标准时间转换为时间戳

public static long Date2ms(String _data){
        SimpleDateFormat format =   new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        try {
            Date date = format.parse(_data);
            return date.getTime();
        }catch(Exception e){
            return 0;
        }
    }

计算时间差

public static  String DateDistance(Date startDate,Date endDate){
        if(startDate == null ||endDate == null){
            return null;
        }
        long timeLong = endDate.getTime() - startDate.getTime();
        if(timeLong<0){
            timeLong=0;
        }
        if (timeLong<60*1000)
            return timeLong/1000 + "秒前";
        else if (timeLong<60*60*1000){
            timeLong = timeLong/1000 /60;
            return timeLong + "分钟前";
        }
        else if (timeLong<60*60*24*1000){
            timeLong = timeLong/60/60/1000;
            return timeLong+"小时前";
        }
        else if ((timeLong/1000/60/60/24)<7){
            timeLong = timeLong/1000/ 60 / 60 / 24;
            return timeLong + "天前";
        }else{
            SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
            return formatter.format(startDate);
        }
    }

计算与当前的时间差

public static  String DateDistance2now(long _ms){
        SimpleDateFormat DateF = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        try {
            Long time=new Long(_ms);
            String d = DateF.format(time);
            Date startDate=DateF.parse(d);
            Date nowDate = Calendar.getInstance().getTime();
            return DateDistance(startDate, nowDate);
        }catch (Exception e){
        }
        return null;
    }

Android下的几种时间格式转换