将日期转换为毫秒到今天,昨天,过去7天,过去30天在Java中

Question

我有一些文件,其创建时间以毫秒为单位.我需要将它们分开为今天,昨天,过去7天,过去30天,超过30天.

我使用了以下代码:convertSimpleDayFormat(1347022979786);

public static String convertSimpleDayFormat(Long val) {


            long displayTime = System.currentTimeMillis() - val;
            displayTime = displayTime/86400000;
            String displayTimeVal = "";
            if(displayTime <1)
            {
                    displayTimeVal = "today";  
            }
            else if(displayTime<2)
            {
                    displayTimeVal = "yesterday";
            } 
            else if(displayTime<7)
            {
                    displayTimeVal = "last7days";
            } 
            else if(displayTime<30)
            {
                    displayTimeVal = "last30days";
            }
            else
            {
                    displayTimeVal = "morethan30days";
            }
            return displayTimeVal;
    }

我减去当前时间并传递毫秒并转换为一天.

但我面临的问题是,我无法计算日期的确切时间(以毫秒为单位).

我想计算今天为:从午夜00:00到午夜24:00.(正好24小时.)

同样,我想将毫秒完全转换为今天,昨天,过去7天,过去30天和超过30天.

Answer 1

private static Calendar clearTimes(Calendar c) {
    c.set(Calendar.HOUR_OF_DAY,0);
    c.set(Calendar.MINUTE,0);
    c.set(Calendar.SECOND,0);
    c.set(Calendar.MILLISECOND,0);
    return c;
}

public static String convertSimpleDayFormat(long val) {
    Calendar today=Calendar.getInstance();
    today=clearTimes(today);

    Calendar yesterday=Calendar.getInstance();
    yesterday.add(Calendar.DAY_OF_YEAR,-1);
    yesterday=clearTimes(yesterday);

    Calendar last7days=Calendar.getInstance();
    last7days.add(Calendar.DAY_OF_YEAR,-7);
    last7days=clearTimes(last7days);

    Calendar last30days=Calendar.getInstance();
    last30days.add(Calendar.DAY_OF_YEAR,-30);
    last30days=clearTimes(last30days);


    if(val >today.getTimeInMillis())
    {
            return "today";  
    }
    else if(val>yesterday.getTimeInMillis())
    {
        return "yesterday";
    } 
    else if(val>last7days.getTimeInMillis())
    {
        return "last7days";
    } 
    else if(val>last30days.getTimeInMillis())
    {
        return "last30days";
    }
    else
    {
        return "morethan30days";
    }
}