DateUtils.java

/**
 *     Copyright SocialSite (C) 2009
 *
 *     This program is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 *
 *     This program is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.socialsite.util;

import java.util.Date;

public class DateUtils
{
	public static String relativeTime(final Date date)
	{
		final int SECOND = 1;
		final int MINUTE = 60 * SECOND;
		final int HOUR = 60 * MINUTE;
		final int DAY = 24 * HOUR;
		final int MONTH = 30 * DAY;

		final long delta = Math.abs(System.currentTimeMillis() - date.getTime()) / 1000;

		if (delta < 1 * MINUTE)
		{
			return delta == 1 ? "one second ago" : delta + " seconds ago";
		}
		if (delta < 2 * MINUTE)
		{
			return "a minute ago";
		}
		if (delta < 45 * MINUTE)
		{
			return delta / MINUTE + " minutes ago";
		}
		if (delta < 90 * MINUTE)
		{
			return "an hour ago";
		}
		if (delta < 24 * HOUR)
		{
			return delta / HOUR + " hours ago";
		}
		if (delta < 48 * HOUR)
		{
			return "yesterday";
		}
		if (delta < 30 * DAY)
		{
			return delta / DAY + " days ago";
		}
		if (delta < 12 * MONTH)
		{
			final long months = delta / MONTH;
			return months <= 1 ? "one month ago" : months + " months ago";
		}
		else
		{
			final long years = delta / MONTH * 12;
			return years <= 1 ? "one year ago" : years + " years ago";
		}
	}
}