java计算时间工具类

package com.date;
02

03
import java.text.ParseException;
04
import java.text.SimpleDateFormat;
05
import java.util.Date;
06

07
public class RelativeDateFormat {
08

09
    private static final long ONE_MINUTE = 60000L;
10
    private static final long ONE_HOUR = 3600000L;
11
    private static final long ONE_DAY = 86400000L;
12
    private static final long ONE_WEEK = 604800000L;
13

14
    private static final String ONE_SECOND_AGO = "秒前";
15
    private static final String ONE_MINUTE_AGO = "分钟前";
16
    private static final String ONE_HOUR_AGO = "小时前";
17
    private static final String ONE_DAY_AGO = "天前";
18
    private static final String ONE_MONTH_AGO = "月前";
19
    private static final String ONE_YEAR_AGO = "年前";
20

21
    public static void main(String[] args) throws ParseException {
22
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:m:s");
23
        Date date = format.parse("2013-11-11 18:35:35");
24
        System.out.println(format(date));
25
    }
26

27
    public static String format(Date date) {
28
        long delta = new Date().getTime() - date.getTime();
29
        if (delta < 1L * ONE_MINUTE) {
30
            long seconds = toSeconds(delta);
31
            return (seconds <= 0 ? 1 : seconds) + ONE_SECOND_AGO;
32
        }
33
        if (delta < 45L * ONE_MINUTE) {
34
            long minutes = toMinutes(delta);
35
            return (minutes <= 0 ? 1 : minutes) + ONE_MINUTE_AGO;
36
        }
37
        if (delta < 24L * ONE_HOUR) {
38
            long hours = toHours(delta);
39
            return (hours <= 0 ? 1 : hours) + ONE_HOUR_AGO;
40
        }
41
        if (delta < 48L * ONE_HOUR) {
42
            return "昨天";
43
        }
44
        if (delta < 30L * ONE_DAY) {
45
            long days = toDays(delta);
46
            return (days <= 0 ? 1 : days) + ONE_DAY_AGO;
47
        }
48
        if (delta < 12L * 4L * ONE_WEEK) {
49
            long months = toMonths(delta);
50
            return (months <= 0 ? 1 : months) + ONE_MONTH_AGO;
51
        } else {
52
            long years = toYears(delta);
53
            return (years <= 0 ? 1 : years) + ONE_YEAR_AGO;
54
        }
55
    }
56

57
    private static long toSeconds(long date) {
58
        return date / 1000L;
59
    }
60

61
    private static long toMinutes(long date) {
62
        return toSeconds(date) / 60L;
63
    }
64

65
    private static long toHours(long date) {
66
        return toMinutes(date) / 60L;
67
    }
68

69
    private static long toDays(long date) {
70
        return toHours(date) / 24L;
71
    }
72

73
    private static long toMonths(long date) {
74
        return toDays(date) / 30L;
75
    }
76

77
    private static long toYears(long date) {
78
        return toMonths(date) / 365L;
79
    }
80

81
}