java - 我创建了一种方法来添加分钟到日期时间，但在 Java 中没有达到预期

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已关闭 4 年前。

这是一个java代码，如果可能的一天，它会添加带有时间小时和分钟的日期

    timeAddition("06/20/2019;23:30", 60, "m")

    public static String timeAddition(String TimeAndDate, int addTime, String units_M_H) {
        try {
            String returnTime = TimeAndDate;
            final long ONE_MINUTE_IN_MILLIS = 60000;

            DateFormat dateFormat = new SimpleDateFormat("MM/dd/YYYY;HH:mm");
            Date date = dateFormat.parse(TimeAndDate);
            Calendar Cal = Calendar.getInstance();

            Cal.setTime(date);

            if (units_M_H.trim().equalsIgnoreCase("h")) {
                Cal.add(Calendar.HOUR_OF_DAY, addTime);
                returnTime = dateFormat.format(Cal.getTime()).toString();
            } else if (units_M_H.trim().equalsIgnoreCase("m")) {
                long timeInMili = date.getTime();
                date = new Date(timeInMili + (addTime * ONE_MINUTE_IN_MILLIS));
                returnTime = dateFormat.format(date);
            }

            return returnTime;
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

预期输出为 06/21/2019;00:30 但实际输出为 12/31/2019;00:30

Answer 1

java.time

不要重新发明轮子，Java 已经拥有执行此类操作的所有工具。请参阅 Java 中内置的类的 java.time 包。请参阅Tutorial .

String timestamp = "06/20/2019;23:30";
LocalDateTime ldt = LocalDateTime.parse(timestamp,
                         DateTimeFormatter.ofPattern("MM/dd/yyyy;HH:mm"));
System.out.println(ldt);
LocalDateTime ldt2 = ldt.plus(60L, ChronoUnit.MINUTES);
System.out.println(ldt2);

将打印您期望的内容。

2019-06-20T23:30
2019-06-21T00:30

希望这有帮助!