从 java.util.Date 中删除时间部分的正确方法是什么？

发布于 2024-12-09 20:49:11 字数 634 浏览 0 评论 0原文

我想实现一个线程安全函数来从 java.util.Date 中删除时间部分。

我尝试了这种方式

private static final DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
public static Date removeTimeFromDate(Date date) {
        Date returnDate = date;

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

        //just have the date remove the time
        String targetDateStr = df.format(date);
        try {
            returnDate = df.parse(targetDateStr);
        } catch (ParseException e) {
        }

        return returnDate;
}

并使用synchronized或threadLocal使其线程安全。但有没有更好的方法在 Java 中实现它。看来这种方式有点啰嗦。我对此并不满意。

原文

I want to implement a thread-safe function to remove the time part from java.util.Date.

I tried this way

private static final DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
public static Date removeTimeFromDate(Date date) {
        Date returnDate = date;

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

        //just have the date remove the time
        String targetDateStr = df.format(date);
        try {
            returnDate = df.parse(targetDateStr);
        } catch (ParseException e) {
        }

        return returnDate;
}

and use synchronized or threadLocal to make it thread-safe.
But it there any better way to implement it in Java. It seems this way is a bit verbose.
I am not satisfied with it.

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

命硬 2024-12-16 20:49:11

Date 对象保存一个变量，该变量表示自 epoch< 以来的毫秒数/a>.因此，您无法“删除”时间部分。您可以做的是将当天的时间设置为零，这意味着它将是当天的 00:00:00 000。这是通过使用 GregorianCalendar 来完成的：

GregorianCalendar gc = new GregorianCalendar();
gc.setTime(date);
gc.set(Calendar.HOUR_OF_DAY, 0);
gc.set(Calendar.MINUTE, 0);
gc.set(Calendar.SECOND, 0);
gc.set(Calendar.MILLISECOND, 0);
Date returnDate = gc.getTime();

A Date object holds a variable wich represents the time as the number of milliseconds since epoch. So, you can't "remove" the time part. What you can do is set the time of that day to zero, which means it will be 00:00:00 000 of that day. This is done by using a GregorianCalendar:

GregorianCalendar gc = new GregorianCalendar();
gc.setTime(date);
gc.set(Calendar.HOUR_OF_DAY, 0);
gc.set(Calendar.MINUTE, 0);
gc.set(Calendar.SECOND, 0);
gc.set(Calendar.MILLISECOND, 0);
Date returnDate = gc.getTime();

回复收藏 0 原文