用Java计算两个日期之间的天数

我想要一个Java程序来计算两个日期之间的天数。

输入第一个日期(德语表示法;有空格:"dd mm yyyy") 输入第二个日期。程序应该计算两个日期之间的天数。

我怎样才能把闰年和夏天时包括进来呢?

我的代码:

import java.util.Calendar;
import java.util.Date;
import java.util.Scanner;

public class NewDateDifference {

    public static void main(String[] args) {

        System.out.print("Insert first date: ");
        Scanner s = new Scanner(System.in);
        String[] eingabe1 = new String[3];

        while (s.hasNext()) {
            int i = 0;
            insert1[i] = s.next();
            if (!s.hasNext()) {
                s.close();
                break;
            }
            i++;
        }

        System.out.print("Insert second date: ");
        Scanner t = new Scanner(System.in);
        String[] insert2 = new String[3];

        while (t.hasNext()) {
            int i = 0;
            insert2[i] = t.next();
            if (!t.hasNext()) {
                t.close();
                break;
            }
            i++;
        }

        Calendar cal = Calendar.getInstance();

        cal.set(Calendar.DAY_OF_MONTH, Integer.parseInt(insert1[0]));
        cal.set(Calendar.MONTH, Integer.parseInt(insert1[1]));
        cal.set(Calendar.YEAR, Integer.parseInt(insert1[2]));
        Date firstDate = cal.getTime();

        cal.set(Calendar.DAY_OF_MONTH, Integer.parseInt(insert2[0]));
        cal.set(Calendar.MONTH, Integer.parseInt(insert2[1]));
        cal.set(Calendar.YEAR, Integer.parseInt(insert2[2]));
        Date secondDate = cal.getTime();


        long diff = secondDate.getTime() - firstDate.getTime();

        System.out.println ("Days: " + diff / 1000 / 60 / 60 / 24);
    }
}

当前回答

下面的方法非常适合我:

public int daysBetween(LocalDate later, LocalDate before) {
        SimpleDateFormat myFormat = new SimpleDateFormat("dd MM yyyy");
        int daysBetween = 0;
        try {
            Date dateBefore = myFormat.parse(localDateToString(before));
            Date dateAfter = myFormat.parse(localDateToString(later));
            long difference = dateAfter.getTime() - dateBefore.getTime();
            daysBetween = (int) (difference / (1000 * 60 * 60 * 24));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return daysBetween;
    }

    public String localDateToString(LocalDate date) {
        DateTimeFormatter myFormat = DateTimeFormatter.ofPattern("dd MM yyyy");
        return date.format(myFormat).toString();
    }

2021-07-16 10:41:50

其他回答

在Java 8中，您可以通过使用LocalDate和DateTimeFormatter来实现这一点。从LocalDate的Javadoc:

LocalDate是一个表示日期的不可变日期时间对象，通常被视为年-月-日。

可以使用DateTimeFormatter构造模式。下面是Javadoc，以及我使用的相关模式字符:

符号-含义-表示-示例 Y -年代-年份- 2004;04 M/L -月份-数字/文本- 7;07年;7月; 7月;J D——一个月的日期——数字——10

下面是例子:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;

public class Java8DateExample {
    public static void main(String[] args) throws IOException {
        final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd MM yyyy");
        final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        final String firstInput = reader.readLine();
        final String secondInput = reader.readLine();
        final LocalDate firstDate = LocalDate.parse(firstInput, formatter);
        final LocalDate secondDate = LocalDate.parse(secondInput, formatter);
        final long days = ChronoUnit.DAYS.between(firstDate, secondDate);
        System.out.println("Days between: " + days);
    }
}

最近的输入/输出示例:

23 01 1997
27 04 1997
Days between: 94

最近的第一个:

27 04 1997
23 01 1997
Days between: -94

你可以用更简单的方法来做:

public static long betweenDates(Date firstDate, Date secondDate) throws IOException
{
    return ChronoUnit.DAYS.between(firstDate.toInstant(), secondDate.toInstant());
}

2015-04-23 02:26:26

Java日期库是出了名的坏。我建议使用Joda Time。它会为你照顾闰年、时区等。

最小工作示例:

import java.util.Scanner;
import org.joda.time.DateTime;
import org.joda.time.Days;
import org.joda.time.LocalDate;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

public class DateTestCase {

    public static void main(String[] args) {

        System.out.print("Insert first date: ");
        Scanner s = new Scanner(System.in);
        String firstdate = s.nextLine();
        System.out.print("Insert second date: ");
        String seconddate = s.nextLine();

        // Formatter
        DateTimeFormatter dateStringFormat = DateTimeFormat
                .forPattern("dd MM yyyy");
        DateTime firstTime = dateStringFormat.parseDateTime(firstdate);
        DateTime secondTime = dateStringFormat.parseDateTime(seconddate);
        int days = Days.daysBetween(new LocalDate(firstTime),
                                    new LocalDate(secondTime)).getDays();
        System.out.println("Days between the two dates " + days);
    }
}

2013-11-23 18:05:46

想要得到只是天(没有时间)，你可以使用ChronoUnit

ChronoUnit.DAYS.between(date1.toLocalDate(), date2.toLocalDate());

2021-06-27 19:17:10

Use:

public int getDifferenceDays(Date d1, Date d2) {
    int daysdiff = 0;
    long diff = d2.getTime() - d1.getTime();
    long diffDays = diff / (24 * 60 * 60 * 1000) + 1;
    daysdiff = (int) diffDays;
    return daysdiff;
}

2014-03-13 12:12:32

下面的方法非常适合我:

public int daysBetween(LocalDate later, LocalDate before) {
        SimpleDateFormat myFormat = new SimpleDateFormat("dd MM yyyy");
        int daysBetween = 0;
        try {
            Date dateBefore = myFormat.parse(localDateToString(before));
            Date dateAfter = myFormat.parse(localDateToString(later));
            long difference = dateAfter.getTime() - dateBefore.getTime();
            daysBetween = (int) (difference / (1000 * 60 * 60 * 24));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return daysBetween;
    }

    public String localDateToString(LocalDate date) {
        DateTimeFormatter myFormat = DateTimeFormatter.ofPattern("dd MM yyyy");
        return date.format(myFormat).toString();
    }

2021-07-16 10:41:50

用Java计算两个日期之间的天数

推荐文章

最新文章

标签