如何在Java中计算“time ago”?

问题

在Ruby on Rails中,有一个功能允许你使用任何日期并打印出"很久以前"的状态。

例如:

8 minutes ago
8 hours ago
8 days ago
8 months ago
8 years ago

在Java中有一种简单的方法吗?


#1 热门回答(153 赞)

看看PrettyTimelibrary。

它使用起来非常简单:

import org.ocpsoft.prettytime.PrettyTime;

PrettyTime p = new PrettyTime();
System.out.println(p.format(new Date()));
// prints "moments ago"

你还可以传入国际化消息的区域设置:

PrettyTime p = new PrettyTime(new Locale("fr"));
System.out.println(p.format(new Date()));
// prints "à l'instant"

如评论中所述,Android具有内置于android.text.format.DateUtils类的此功能。


#2 热门回答(65 赞)

你考虑过TimeUnitenum吗?它对于这种事情非常有用

try {
        SimpleDateFormat format = new SimpleDateFormat("dd/MM/yyyy");
        Date past = format.parse("01/10/2010");
        Date now = new Date();

        System.out.println(TimeUnit.MILLISECONDS.toMillis(now.getTime() - past.getTime()) + " milliseconds ago");
        System.out.println(TimeUnit.MILLISECONDS.toMinutes(now.getTime() - past.getTime()) + " minutes ago");
        System.out.println(TimeUnit.MILLISECONDS.toHours(now.getTime() - past.getTime()) + " hours ago");
        System.out.println(TimeUnit.MILLISECONDS.toDays(now.getTime() - past.getTime()) + " days ago");
    }
    catch (Exception j){
        j.printStackTrace();
    }

#3 热门回答(41 赞)

public class TimeUtils {

      public final static long ONE_SECOND = 1000;
      public final static long SECONDS = 60;

      public final static long ONE_MINUTE = ONE_SECOND * 60;
      public final static long MINUTES = 60;

      public final static long ONE_HOUR = ONE_MINUTE * 60;
      public final static long HOURS = 24;

      public final static long ONE_DAY = ONE_HOUR * 24;

      private TimeUtils() {
      }

      /**
       * converts time (in milliseconds) to human-readable format
       *  "<w> days, <x> hours, <y> minutes and (z) seconds"
       */
      public static String millisToLongDHMS(long duration) {
        StringBuffer res = new StringBuffer();
        long temp = 0;
        if (duration >= ONE_SECOND) {
          temp = duration / ONE_DAY;
          if (temp > 0) {
            duration -= temp * ONE_DAY;
            res.append(temp).append(" day").append(temp > 1 ? "s" : "")
               .append(duration >= ONE_MINUTE ? ", " : "");
          }

          temp = duration / ONE_HOUR;
          if (temp > 0) {
            duration -= temp * ONE_HOUR;
            res.append(temp).append(" hour").append(temp > 1 ? "s" : "")
               .append(duration >= ONE_MINUTE ? ", " : "");
          }

          temp = duration / ONE_MINUTE;
          if (temp > 0) {
            duration -= temp * ONE_MINUTE;
            res.append(temp).append(" minute").append(temp > 1 ? "s" : "");
          }

          if (!res.toString().equals("") && duration >= ONE_SECOND) {
            res.append(" and ");
          }

          temp = duration / ONE_SECOND;
          if (temp > 0) {
            res.append(temp).append(" second").append(temp > 1 ? "s" : "");
          }
          return res.toString();
        } else {
          return "0 second";
        }
      }


      public static void main(String args[]) {
        System.out.println(millisToLongDHMS(123));
        System.out.println(millisToLongDHMS((5 * ONE_SECOND) + 123));
        System.out.println(millisToLongDHMS(ONE_DAY + ONE_HOUR));
        System.out.println(millisToLongDHMS(ONE_DAY + 2 * ONE_SECOND));
        System.out.println(millisToLongDHMS(ONE_DAY + ONE_HOUR + (2 * ONE_MINUTE)));
        System.out.println(millisToLongDHMS((4 * ONE_DAY) + (3 * ONE_HOUR)
            + (2 * ONE_MINUTE) + ONE_SECOND));
        System.out.println(millisToLongDHMS((5 * ONE_DAY) + (4 * ONE_HOUR)
            + ONE_MINUTE + (23 * ONE_SECOND) + 123));
        System.out.println(millisToLongDHMS(42 * ONE_DAY));
        /*
          output :
                0 second
                5 seconds
                1 day, 1 hour
                1 day and 2 seconds
                1 day, 1 hour, 2 minutes
                4 days, 3 hours, 2 minutes and 1 second
                5 days, 4 hours, 1 minute and 23 seconds
                42 days
         */
    }
}

更多@ Format a duration in milliseconds into a human-readable format