在 Java 静态方法中，使用“today”和“yesterday”字符串简化日期对象的替换

replace date java simplify

2022-09-04 05:05:55

我有以下方法，如果没有别的，我想缩短或更快。欢迎大家提出意见：

Bellow方法获取一个日期对象，对其进行格式化（“EEE hh：mma MMM d，yyyy”），然后确定日期是今天还是昨天，如果是，则返回“（昨天|今天）hh：mma“格式的字符串。

    public static String formatToYesterdayOrToday(String date) {
    SimpleDateFormat sdf = new SimpleDateFormat("EEE hh:mma MMM d, yyyy");
    Date in = null;

    try {
        in = sdf.parse(date);
    } catch (ParseException e) {
        log.debug("Date parsing error:", e);
    }

    Calendar x = Calendar.getInstance();
    x.setTime(in);

    String hour = Integer.toString(x.get(Calendar.HOUR));
    String minute = Integer.toString(x.get(Calendar.MINUTE));
    String pm_am = x.get(Calendar.AM_PM) == Calendar.AM ? "AM" : "PM";

    x.set(Calendar.HOUR, 0);
    x.set(Calendar.HOUR_OF_DAY, 0);
    x.set(Calendar.MINUTE, 0);
    x.set(Calendar.SECOND, 0);
    x.set(Calendar.MILLISECOND, 0);

    Calendar today = Calendar.getInstance();
    today.set(Calendar.HOUR, 0);
    today.set(Calendar.HOUR_OF_DAY, 0);
    today.set(Calendar.MINUTE, 0);
    today.set(Calendar.SECOND, 0);
    today.set(Calendar.MILLISECOND, 0);

    Calendar yesterday = Calendar.getInstance();
    yesterday.set(Calendar.HOUR, 0);
    yesterday.set(Calendar.HOUR_OF_DAY, 0);
    yesterday.set(Calendar.MINUTE, 0);
    yesterday.set(Calendar.SECOND, 0);
    yesterday.set(Calendar.MILLISECOND, 0);
    yesterday.add(Calendar.DATE, -1);

    if (x.compareTo(today) == 0) {
        return "Today " + hour + ":" + minute + pm_am;
    }
    if (x.compareTo(yesterday) == 0) {
        return "Yesterday " + hour + ":" + minute + pm_am;
    }
    return date;
}

答案 1

以下是使用标准 API 改进它的方法：

public static String formatToYesterdayOrToday(String date) throws ParseException {
    Date dateTime = new SimpleDateFormat("EEE hh:mma MMM d, yyyy").parse(date);
    Calendar calendar = Calendar.getInstance();
    calendar.setTime(dateTime);
    Calendar today = Calendar.getInstance();
    Calendar yesterday = Calendar.getInstance();
    yesterday.add(Calendar.DATE, -1);
    DateFormat timeFormatter = new SimpleDateFormat("hh:mma");

    if (calendar.get(Calendar.YEAR) == today.get(Calendar.YEAR) && calendar.get(Calendar.DAY_OF_YEAR) == today.get(Calendar.DAY_OF_YEAR)) {
        return "Today " + timeFormatter.format(dateTime);
    } else if (calendar.get(Calendar.YEAR) == yesterday.get(Calendar.YEAR) && calendar.get(Calendar.DAY_OF_YEAR) == yesterday.get(Calendar.DAY_OF_YEAR)) {
        return "Yesterday " + timeFormatter.format(dateTime);
    } else {
        return date;
    }
}

以下是你如何用Jodatime做到这一点：

public static String formatToYesterdayOrToday(String date) {
    DateTime dateTime = DateTimeFormat.forPattern("EEE hh:mma MMM d, yyyy").parseDateTime(date);
    DateTime today = new DateTime();
    DateTime yesterday = today.minusDays(1);
    DateTimeFormatter timeFormatter = DateTimeFormat.forPattern("hh:mma");

    if (dateTime.toLocalDate().equals(today.toLocalDate())) {
        return "Today " + timeFormatter.print(dateTime);
    } else if (dateTime.toLocalDate().equals(yesterday.toLocalDate())) {
        return "Yesterday " + timeFormatter.print(dateTime);
    } else {
        return date;
    }
}

答案 2

你写了“欢迎所有评论”，所以这是我使用joda-time的方式。:)

我喜欢以iPhone最近通话的简短而智能的方式显示日期和时间（类似于谷歌波浪帖子）。如果今天是“hh：mm”，则为“昨天”，如果<7天，则为工作日的名称，否则为yyyy-MM-dd。

private static boolean isToday (DateTime dateTime) {
   DateMidnight today = new DateMidnight();
   return today.equals(dateTime.toDateMidnight());
}

private static boolean isYesterday (DateTime dateTime) {
   DateMidnight yesterday = (new DateMidnight()).minusDays(1);
   return yesterday.equals(dateTime.toDateMidnight());
}

private static String getDayString(Date date) {
    String s;

    if (isToday(new DateTime(date)))
        s = "Today";
    else if (isYesterday(new DateTime(date)))
        s = "Yesterday";
    else
        s = weekdayFormat.format(date);

    return s;
}

public static String getDateString_shortAndSmart(Date date) {
    String s;

    DateTime nowDT = new DateTime();
    DateTime dateDT = new DateTime(date);
    int days = Days.daysBetween(dateDT, nowDT).getDays();

    if (isToday(new DateTime(date)))
        s = getHourMinuteString(date);
    else if (days < 7)
        s = getDayString(date);
    else
        s = getDateString(date);

    return s;
}

其中，我使用一组 SimpleDateFormat（如上面的 weekdayFormat）将时间格式化为所需的字符串，其中 DateTime 和 DateMidnight 是 joda 时间类。

在这些情况下，两个 DateTime：s 之间经过的天数不如人们如何定义谈论它的时间相关。而不是计算天数（或毫秒，因为我看到有些人这样做），DateMidnight在这里派上用场，尽管其他方法也可以。:)