java计算时间工具类

package com.date;
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import java.text.ParseException;
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import java.text.SimpleDateFormat;
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import java.util.Date;
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public class RelativeDateFormat {
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private static final long ONE_MINUTE = 60000L;
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private static final long ONE_HOUR = 3600000L;
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private static final long ONE_DAY = 86400000L;
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private static final long ONE_WEEK = 604800000L;
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private static final String ONE_SECOND_AGO = "秒前";
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private static final String ONE_MINUTE_AGO = "分钟前";
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private static final String ONE_HOUR_AGO = "小时前";
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private static final String ONE_DAY_AGO = "天前";
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private static final String ONE_MONTH_AGO = "月前";
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private static final String ONE_YEAR_AGO = "年前";
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public static void main(String[] args) throws ParseException {
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SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:m:s");
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Date date = format.parse("2013-11-11 18:35:35");
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System.out.println(format(date));
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}
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public static String format(Date date) {
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long delta = new Date().getTime() - date.getTime();
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if (delta < 1L * ONE_MINUTE) {
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long seconds = toSeconds(delta);
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return (seconds <= 0 ? 1 : seconds) + ONE_SECOND_AGO;
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}
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if (delta < 45L * ONE_MINUTE) {
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long minutes = toMinutes(delta);
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return (minutes <= 0 ? 1 : minutes) + ONE_MINUTE_AGO;
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}
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if (delta < 24L * ONE_HOUR) {
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long hours = toHours(delta);
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return (hours <= 0 ? 1 : hours) + ONE_HOUR_AGO;
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}
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if (delta < 48L * ONE_HOUR) {
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return "昨天";
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}
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if (delta < 30L * ONE_DAY) {
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long days = toDays(delta);
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return (days <= 0 ? 1 : days) + ONE_DAY_AGO;
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}
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if (delta < 12L * 4L * ONE_WEEK) {
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long months = toMonths(delta);
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return (months <= 0 ? 1 : months) + ONE_MONTH_AGO;
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} else {
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long years = toYears(delta);
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return (years <= 0 ? 1 : years) + ONE_YEAR_AGO;
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}
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}
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private static long toSeconds(long date) {
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return date / 1000L;
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}
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private static long toMinutes(long date) {
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return toSeconds(date) / 60L;
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}
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private static long toHours(long date) {
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return toMinutes(date) / 60L;
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}
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private static long toDays(long date) {
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return toHours(date) / 24L;
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}
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private static long toMonths(long date) {
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return toDays(date) / 30L;
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}
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private static long toYears(long date) {
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return toMonths(date) / 365L;
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}
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}