Java 中的 PHP strtotime() ？

我正在寻找一种简单的方法来从用户可能输入的任何类型的时间输入生成MySQL DATETIME。 PHP 的 strtotime() 函数使这一切变得简单，它可以执行以下操作：

strtotime('2004-02-12T15:19:21+00:00');

strtotime('2000 年 12 月 21 日星期四 16:01:07 +0200');

strtotime('1 月 1 日星期一');

strtotime('明天');

strtotime('-1周2天4小时2秒');

Outputs:

2004-02-12 07:02:21

2000-12-21 06:12:07

2009-01-01 12:01:00

2009-02-12 12:02:00

2009-02-06 09:02:41

我想要这个 Java 版本！

我尝试实现一个简单的（静态）类来模拟 PHP 的一些模式strtotime。这个类的设计目的是开放修改（只需添加一个新的Matcher via registerMatcher):

public final class strtotime {

    private static final List<Matcher> matchers;

    static {
        matchers = new LinkedList<Matcher>();
        matchers.add(new NowMatcher());
        matchers.add(new TomorrowMatcher());
        matchers.add(new DateFormatMatcher(new SimpleDateFormat("yyyy.MM.dd G 'at' HH:mm:ss z")));
        matchers.add(new DateFormatMatcher(new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z")));
        matchers.add(new DateFormatMatcher(new SimpleDateFormat("yyyy MM dd")));
        // add as many format as you want 
    }

    // not thread-safe
    public static void registerMatcher(Matcher matcher) {
        matchers.add(matcher);
    }

    public static interface Matcher {

        public Date tryConvert(String input);
    }

    private static class DateFormatMatcher implements Matcher {

        private final DateFormat dateFormat;

        public DateFormatMatcher(DateFormat dateFormat) {
            this.dateFormat = dateFormat;
        }

        public Date tryConvert(String input) {
            try {
                return dateFormat.parse(input);
            } catch (ParseException ex) {
                return null;
            }
        }
    }

    private static class NowMatcher implements Matcher {

        private final Pattern now = Pattern.compile("now");

        public Date tryConvert(String input) {
            if (now.matcher(input).matches()) {
                return new Date();
            } else {
                return null;
            }
        }
    }

    private static class TomorrowMatcher implements Matcher {

        private final Pattern tomorrow = Pattern.compile("tomorrow");

        public Date tryConvert(String input) {
            if (tomorrow.matcher(input).matches()) {
                Calendar calendar = Calendar.getInstance();
                calendar.add(Calendar.DAY_OF_YEAR, +1);
                return calendar.getTime();
            } else {
                return null;
            }
        }
    }

    public static Date strtotime(String input) {
        for (Matcher matcher : matchers) {
            Date date = matcher.tryConvert(input);

            if (date != null) {
                return date;
            }
        }

        return null;
    }

    private strtotime() {
        throw new UnsupportedOperationException();
    }
}

Usage

基本用法：

 Date now = strtotime("now");
 Date tomorrow = strtotime("tomorrow");

Wed Aug 12 22:18:57 CEST 2009
Thu Aug 13 22:18:57 CEST 2009
  

延伸

例如我们添加日子匹配器:

strtotime.registerMatcher(new Matcher() {

    private final Pattern days = Pattern.compile("[\\-\\+]?\\d+ days");

    public Date tryConvert(String input) {

        if (days.matcher(input).matches()) {
            int d = Integer.parseInt(input.split(" ")[0]);
            Calendar calendar = Calendar.getInstance();
            calendar.add(Calendar.DAY_OF_YEAR, d);
            return calendar.getTime();
        }

        return null;
    }
});

那么你可以写：

System.out.println(strtotime("3 days"));
System.out.println(strtotime("-3 days"));

(now is Wed Aug 12 22:18:57 CEST 2009)

Sat Aug 15 22:18:57 CEST 2009
Sun Aug 09 22:18:57 CEST 2009