如何使用 Joda-Time 计算从现在起经过的时间？

Question

I need to calculate the time elapsed from one specific date till now and display it with the same format as StackOverflow questions, ie:

15s ago
2min ago
2hours ago
2days ago
25th Dec 08

Do you know how to achieve it with the Java Joda-Time library ? Is there a helper method out there that already implements it, or should I write the algorithm myself?

Answer 1

To calculate the elapsed time with JodaTime, use Period . To format the elapsed time in the desired human representation, use PeriodFormatter which you can build by PeriodFormatterBuilder .

Here's a kickoff example:

DateTime myBirthDate = new DateTime(1978, 3, 26, 12, 35, 0, 0);
DateTime now = new DateTime();
Period period = new Period(myBirthDate, now);

PeriodFormatter formatter = new PeriodFormatterBuilder()
    .appendSeconds().appendSuffix(" seconds ago\n")
    .appendMinutes().appendSuffix(" minutes ago\n")
    .appendHours().appendSuffix(" hours ago\n")
    .appendDays().appendSuffix(" days ago\n")
    .appendWeeks().appendSuffix(" weeks ago\n")
    .appendMonths().appendSuffix(" months ago\n")
    .appendYears().appendSuffix(" years ago\n")
    .printZeroNever()
    .toFormatter();

String elapsed = formatter.print(period);
System.out.println(elapsed);

This prints by now

3 seconds ago
51 minutes ago
7 hours ago
6 days ago
10 months ago
31 years ago

^{_{(Cough, old, cough)}} You see that I've taken months and years into account as well and configured it to omit the values when those are zero.

Answer 2

Use PrettyTime for Simple Elapsed Time.

I tried HumanTime as @sfussenegger answered and using JodaTime's Period but the easiest and cleanest method for human readable elapsed time that I found was the PrettyTime library.

Here's a couple of simple examples with input and output:

Five Minutes Ago

DateTime fiveMinutesAgo = DateTime.now().minusMinutes( 5 );

new PrettyTime().format( fiveMinutesAgo.toDate() );

// Outputs: "5 minutes ago"

Awhile Ago

DateTime birthday = new DateTime(1978, 3, 26, 12, 35, 0, 0);

new PrettyTime().format( birthday.toDate() );

// Outputs: "4 decades ago"

CAUTION: I've tried playing around with the library's more precise functionality, but it produces some odd results so use it with care and in non-life threatening projects.

JP

Answer 3

You can do this with a PeriodFormatter but you don't have to go to the effort of making your own PeriodFormatBuilder as in other answers . If it suits your case, you can just use the default formatter:

Period period = new Period(startDate, endDate);
System.out.println(PeriodFormat.getDefault().print(period))

(hat tip to this answer on a similar question, I'm cross-posting for discoverability)

Answer 4

有一个叫做HumanTime的小助手类，我很满意。

Answer 5

This is using mysql timestamp to get elapsed time to now. Singular and plular is managed. Only display the max time.

NOTE: set your own timezone.

String getElapsedTime(String strMysqlTimestamp) {
    
    DateTimeFormatter formatter = DateTimeFormat.forPattern("YYYY-MM-dd HH:mm:ss.S");
    DateTime mysqlDate = formatter.parseDateTime(strMysqlTimestamp).
                         withZone(DateTimeZone.forID("Asia/Kuala_Lumpur"));
    
    DateTime now = new DateTime();
    Period period = new Period(mysqlDate, now);
    
    int seconds = period.getSeconds();
    int minutes = period.getMinutes();
    int hours = period.getHours();
    int days = period.getDays();
    int weeks = period.getWeeks();
    int months = period.getMonths();
    int years = period.getYears();
    
    String elapsedTime = "";
    if (years != 0)
        if (years == 1)
            elapsedTime = years + " year ago";
        else
            elapsedTime = years + " years ago";
    else if (months != 0)
        if (months == 1)
            elapsedTime = months + " month ago";
        else
            elapsedTime = months + " months ago";
    else if (weeks != 0)
        if (weeks == 1)
            elapsedTime = weeks + " week ago";
        else
            elapsedTime = weeks + " weeks ago";
    else if (days != 0)
        if (days == 1)
            elapsedTime = days + " day ago";
        else
            elapsedTime = days + " days ago";
    else if (hours != 0)
        if (hours == 1)
            elapsedTime = hours + " hour ago";
        else
            elapsedTime = hours + " hours ago";
    else if (minutes != 0)
        if (minutes == 1)
            elapsedTime = minutes + " minute ago";
        else
            elapsedTime = minutes + " minutes ago";
    else if (seconds != 0)
        if (seconds == 1)
            elapsedTime = seconds + " second ago";
        else
            elapsedTime = seconds + " seconds ago";   
    
    return elapsedTime;
} 

Answer 6

Here is my solution , using joda time .

private static final int SECOND_MILLIS = 1000;
private static final int MINUTE_MILLIS = 60 * SECOND_MILLIS;
private static final int HOUR_MILLIS = 60 * MINUTE_MILLIS;
private static final int DAY_MILLIS = 24 * HOUR_MILLIS;

public static String getTimeAgo(long time)
{
    if(time < 1000000000000L)
    {
        time *= 1000;
    }

    long now = System.currentTimeMillis();

    if(time > now || time <= 0)
    {
        return null;
    }

    final long diff = now - time;

    if(diff < MINUTE_MILLIS)
    {
        return "just now";
    }
    else if(diff < 2 * MINUTE_MILLIS)
    {
        return "a minute ago";
    }
    else if(diff < 50 * MINUTE_MILLIS)
    {
        return diff / MINUTE_MILLIS + " minutes ago";
    }
    else if(diff < 90 * MINUTE_MILLIS)
    {
        return "an hour ago";
    }
    else if(diff < 24 * HOUR_MILLIS)
    {
        return diff / HOUR_MILLIS + " hours ago";
    }
    else if(diff < 48 * HOUR_MILLIS)
    {
        return "yesterday";
    }
    else
    {
        return diff / DAY_MILLIS + " days ago";
    }
}

How to use the method:

Just call the method and pass in time in milliseconds .

For example :

long now = System.currentTimeMillis();
getTimeAgo(now);