评论时间戳格式化

如图：

注意，评论时间戳的格式，刚才，几小时之前，几天之前.....

实现需要一个时间格式的工具类，如果用java.util.Date当然也可以实现，这里说的是更方便的joda-time。

maven地址：http://search.maven.org/#search%7Cga%7C1%7Cjoda-time

工具类如下：

package com.chunsheng.me.timestamp;

import java.util.Date;
import java.util.concurrent.TimeUnit;

import org.joda.time.DateTime;
import org.joda.time.Days;
import org.joda.time.Hours;
import org.joda.time.Minutes;
import org.joda.time.Months;
import org.joda.time.Weeks;
import org.joda.time.Years;

class TimeStampFormatter {

    /**
     * For use with java.util.Date
     */
    public String format(Date timestamp) {
        long millisFromNow = getMillisFromNow(timestamp);

        long minutesFromNow = TimeUnit.MILLISECONDS.toMinutes(millisFromNow);
        if (minutesFromNow < 1) {
            return "just now";
        }
        long hoursFromNow = TimeUnit.MILLISECONDS.toHours(millisFromNow);
        if (hoursFromNow < 1) {
            return formatMinutes(minutesFromNow);
        }
        long daysFromNow = TimeUnit.MILLISECONDS.toDays(millisFromNow);
        if (daysFromNow < 1) {
            return formatHours(hoursFromNow);
        }
        long weeksFromNow = TimeUnit.MILLISECONDS.toDays(millisFromNow) / 7;
        if (weeksFromNow < 1) {
            return formatDays(daysFromNow);
        }
        long monthsFromNow = TimeUnit.MILLISECONDS.toDays(millisFromNow) / 30;
        if (monthsFromNow < 1) {
            return formatWeeks(weeksFromNow);
        }
        long yearsFromNow = TimeUnit.MILLISECONDS.toDays(millisFromNow) / 365;
        if (yearsFromNow < 1) {
            return formatMonths(monthsFromNow);
        }
        return formatYears(yearsFromNow);
    }

    private long getMillisFromNow(Date commentedAt) {
        long commentedAtMillis = commentedAt.getTime();
        long nowMillis = System.currentTimeMillis();
        return nowMillis - commentedAtMillis;
    }

    /**
     * For use with org.joda.DateTime
     */
    public String format(DateTime commentedAt) {
        DateTime now = DateTime.now();
        Minutes minutesBetween = Minutes.minutesBetween(commentedAt, now);
        if (minutesBetween.isLessThan(Minutes.ONE)) {
            return "just now";
        }
        Hours hoursBetween = Hours.hoursBetween(commentedAt, now);
        if (hoursBetween.isLessThan(Hours.ONE)) {
            return formatMinutes(minutesBetween.getMinutes());
        }
        Days daysBetween = Days.daysBetween(commentedAt, now);
        if (daysBetween.isLessThan(Days.ONE)) {
            return formatHours(hoursBetween.getHours());
        }
        Weeks weeksBetween = Weeks.weeksBetween(commentedAt, now);
        if (weeksBetween.isLessThan(Weeks.ONE)) {
            return formatDays(daysBetween.getDays());
        }
        Months monthsBetween = Months.monthsBetween(commentedAt, now);
        if (monthsBetween.isLessThan(Months.ONE)) {
            return formatWeeks(weeksBetween.getWeeks());
        }
        Years yearsBetween = Years.yearsBetween(commentedAt, now);
        if (yearsBetween.isLessThan(Years.ONE)) {
            return formatMonths(monthsBetween.getMonths());
        }
        return formatYears(yearsBetween.getYears());
    }

    private String formatMinutes(long minutes) {
        return format(minutes, " minute ago", " minutes ago");
    }

    private String formatHours(long hours) {
        return format(hours, " hour ago", " hours ago");
    }

    private String formatDays(long days) {
        return format(days, " day ago", " days ago");
    }

    private String formatWeeks(long weeks) {
        return format(weeks, " week ago", " weeks ago");
    }

    private String formatMonths(long months) {
        return format(months, " month ago", " months ago");
    }

    private String formatYears(long years) {
        return format(years, " year ago", " years ago");
    }

    private String format(long hand, String singular, String plural) {
        if (hand == 1) {
            return hand + singular;
        } else {
            return hand + plural;
        }
    }

}

　　

PS：

Date之常用：

 private static Date date(String string) {
        try {
            return new SimpleDateFormat("yyyy-MM-dd HH:mm", Locale.UK).parse(string);
        } catch (ParseException e) {
            throw new IllegalArgumentException(e);
        }
    }

    private static Date dateIso(String string){
        try {
            SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.getDefault());
            simpleDateFormat.setTimeZone(TimeZone.getTimeZone("GMT"));
            return simpleDateFormat.parse(string);
        } catch (ParseException e) {
            throw new IllegalArgumentException(e);
        }
    }

　　

dateIso("2014-02-14T18:40:50Z")


TimeStampFormatter t = new TimeStampFormatter();
		//new SimpleDateFormat("yyyy-MM-dd HH:mm", Locale.UK).parse(string)
		try {
			System.out.println(t.format(new SimpleDateFormat("yyyy-MM-dd HH:mm", Locale.CHINA).parse("2016-02-14 09:00")));
		} catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

　　

PS：Date实现：

import java.util.Date;
import java.util.concurrent.TimeUnit;
 
class TimeStampFormatter {
 
    /**
     * For use with java.util.Date
     */
    public String format(Date timestamp) {
        long millisFromNow = getMillisFromNow(timestamp);
 
        long minutesFromNow = TimeUnit.MILLISECONDS.toMinutes(millisFromNow);
        if (minutesFromNow < 1) {
            return "just now";
        }
        long hoursFromNow = TimeUnit.MILLISECONDS.toHours(millisFromNow);
        if (hoursFromNow < 1) {
            return formatMinutes(minutesFromNow);
        }
        long daysFromNow = TimeUnit.MILLISECONDS.toDays(millisFromNow);
        if (daysFromNow < 1) {
            return formatHours(hoursFromNow);
        }
        long weeksFromNow = TimeUnit.MILLISECONDS.toDays(millisFromNow) / 7;
        if (weeksFromNow < 1) {
            return formatDays(daysFromNow);
        }
        long monthsFromNow = TimeUnit.MILLISECONDS.toDays(millisFromNow) / 30;
        if (monthsFromNow < 1) {
            return formatWeeks(weeksFromNow);
        }
        long yearsFromNow = TimeUnit.MILLISECONDS.toDays(millisFromNow) / 365;
        if (yearsFromNow < 1) {
            return formatMonths(monthsFromNow);
        }
        return formatYears(yearsFromNow);
    }
 
    private long getMillisFromNow(Date commentedAt) {
        long commentedAtMillis = commentedAt.getTime();
        long nowMillis = System.currentTimeMillis();
        return nowMillis - commentedAtMillis;
    }
 
    private String formatMinutes(long minutes) {
        return format(minutes, " minute ago", " minutes ago");
    }
 
    private String formatHours(long hours) {
        return format(hours, " hour ago", " hours ago");
    }
 
    private String formatDays(long days) {
        return format(days, " day ago", " days ago");
    }
 
    private String formatWeeks(long weeks) {
        return format(weeks, " week ago", " weeks ago");
    }
 
    private String formatMonths(long months) {
        return format(months, " month ago", " months ago");
    }
 
    private String formatYears(long years) {
        return format(years, " year ago", " years ago");
    }
 
    private String format(long hand, String singular, String plural) {
        if (hand == 1) {
            return hand + singular;
        } else {
            return hand + plural;
        }
    }
}

　　

from：http://blog.blundellapps.co.uk/creating-comments-with-timestamps-like-youtube/

import java.util.Date;
import java.util.concurrent.TimeUnit;
 
import org.junit.Test;
 
import static org.junit.Assert.assertEquals;
 
public class JavaUtilDate_TimeStampFormatterTest {
 
    private static final int DAYS_IN_A_WEEK = 7;
    private static final int AVERAGE_DAYS_IN_A_MONTH = 30;
    private static final int DAYS_IN_YEAR = 365; // We don't need the level of accuracy of leap years
 
    @Test
    public void givenCommentedUnder60SecondsAgo_thenFormatSaysJustNow() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusSeconds(59, now());
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("just now", commentedAtFormatted);
    }
 
    @Test
    public void givenCommented1MinuteAgo_thenFormatSays1MinuteAgo() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusMinutes(1, now());
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("1 minute ago", commentedAtFormatted);
    }
 
    @Test
    public void givenCommentedUnder60MinuteAgo_thenFormatSaysXMinutesAgo() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusMinutes(59, minusSeconds(59, now()));
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("59 minutes ago", commentedAtFormatted);
    }
 
    @Test
    public void givenCommented1HourAgo_thenFormatSays1HourAgo() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusHours(1, now());
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("1 hour ago", commentedAtFormatted);
    }
 
    @Test
    public void givenCommentedUnder24HoursAgo_thenFormatSaysXHoursAgo() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusHours(23, minusMinutes(59, now()));
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("23 hours ago", commentedAtFormatted);
    }
 
    @Test
    public void givenCommented1DayAgo_thenFormatSays1DayAgo() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusDays(1, now());
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("1 day ago", commentedAtFormatted);
    }
 
    @Test
    public void givenCommentedLessThan7DayAgo_thenFormatSaysXDaysAgo() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusDays(6, minusHours(23, minusMinutes(59, now())));
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("6 days ago", commentedAtFormatted);
    }
 
    @Test
    public void givenCommented1WeekAgo_thenFormatSays1WeekAgo() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusWeeks(1, now());
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("1 week ago", commentedAtFormatted);
    }
 
    @Test
    public void givenCommentedLessThan4WeeksAgo_thenFormatSaysXWeeksAgo() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusWeeks(3, minusDays(6, minusHours(23, minusMinutes(59, now()))));
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("3 weeks ago", commentedAtFormatted);
    }
 
    @Test
    public void givenCommented1MonthAgo_thenFormatSays1MonthAgo() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusMonths(1, now());
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("1 month ago", commentedAtFormatted);
    }
 
    @Test
    public void givenCommentedLessThan1YearAgo_thenFormatSaysXMonthsAgo() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusMonths(11, minusWeeks(3, minusDays(6, minusHours(23, minusMinutes(59, now())))));
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("11 months ago", commentedAtFormatted);
    }
 
    @Test
    public void givenCommented1YearAgo_thenFormatSays1YearAgo() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusYears(1, now());
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("1 year ago", commentedAtFormatted);
    }
 
    @Test
    public void givenCommentedOver1YearAgo_thenFormatSaysXYearsAgo() throws Exception {
        TimeStampFormatter formatter = new TimeStampFormatter();
        Date commentedAt = minusYears(2, minusMonths(11, minusWeeks(3, minusDays(6, minusHours(23, minusMinutes(59, now()))))));
 
        String commentedAtFormatted = formatter.format(commentedAt);
 
        assertEquals("2 years ago", commentedAtFormatted);
    }
 
    private Date minusSeconds(int seconds, Date date) {
        return minus(date, TimeUnit.SECONDS.toMillis(seconds));
    }
 
    private Date minusMinutes(int minutes, Date date) {
        return minus(date, TimeUnit.MINUTES.toMillis(minutes));
    }
 
    private Date minusHours(int hours, Date date) {
        return minus(date, TimeUnit.HOURS.toMillis(hours));
    }
 
    private Date minusDays(int days, Date date) {
        return minus(date, TimeUnit.DAYS.toMillis(days));
    }
 
    private Date minusWeeks(int weeks, Date date) {
        return minus(date, TimeUnit.DAYS.toMillis(weeks * DAYS_IN_A_WEEK));
    }
 
    private Date minusMonths(int months, Date date) {
        return minus(date, TimeUnit.DAYS.toMillis(months * AVERAGE_DAYS_IN_A_MONTH));
    }
 
    private Date minusYears(int years, Date date) {
        return minus(date, TimeUnit.DAYS.toMillis(years * DAYS_IN_YEAR));
    }
 
    private Date minus(Date date, long minutesInMillis) {
        date.setTime(date.getTime() - minutesInMillis);
        return date;
    }
 
    private Date now() {
        return new Date();
    }
}