Java方法来查找年，月和日2个日期对象之间的差异

Question

我有一个开始日期和结束日期。两个日期之间的持续时间应采用年、月和日的形式。我是java新手。 当我运行以下方法时，我得到的结果是 0 年 12 个月 1 天。 请建议一种替代方法，以获得准确的年、月和日差异。

import java.sql.Date;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;

public class Duration {

    private String getAssignmentDuration(java.util.Date oldDate, java.util.Date newDate) {
        Calendar c1 = Calendar.getInstance();
        Calendar c2 = Calendar.getInstance();
        if (oldDate.compareTo(newDate) > 0) {
            c1.setTime(newDate);
            c2.setTime(oldDate);
        } else {
            System.out.println("invalid");
            return "Invalid selection";

        }
        int year = 0;
        int month = 0;
        int days = 0;
        boolean doneMonth = false;
        boolean doneYears = false;
        while (c1.before(c2)) {
            //log.debug("Still in Loop");
            if (!doneYears) {
                c1.add(Calendar.YEAR, 1);
                year++;
            }
            if (c1.after(c2) || doneYears) {
                if (!doneYears) {
                    doneYears = true;
                    year--;
                    c1.add(Calendar.YEAR, -1);
                }   
                if (!doneMonth) {
                    c1.add(Calendar.MONTH, 1);
                    month++;
                }
                if (c1.after(c2) || doneMonth) {
                    if (!doneMonth) {
                        doneMonth = true;
                        month--;
                        c1.add(Calendar.MONTH, -1);
                    }

                    c1.add(Calendar.DATE, 1);
                    days++;
                    if (c1.after(c2)) {
                        days--;
                    }
                    // this will not be executed
                    if (days == 31 || month==12) {
                        break;
                    }
                }
            }
        }
        System.out.println(year + " years, " + month + " months, " + days + " days");
        return year + " years, " + month + " months, " + days + " days";

    }


    public static void main(String[] args) {
        Duration d1= new Duration();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
        java.util.Date oldDate = null;
        try {
            oldDate = sdf.parse("2012/08/29");
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        java.util.Date newDate = null;
        try {
            newDate = sdf.parse("2013/08/31");
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        d1.getAssignmentDuration(oldDate, newDate);
    }

}

Answer 1

 public static String getDateDifferenceInDDMMYYYY(Date from, Date to) {
        Calendar fromDate=Calendar.getInstance();
        Calendar toDate=Calendar.getInstance();
        fromDate.setTime(from);
        toDate.setTime(to);
        int increment = 0;
        int year,month,day;
        System.out.println(fromDate.getActualMaximum(Calendar.DAY_OF_MONTH));
        if (fromDate.get(Calendar.DAY_OF_MONTH) > toDate.get(Calendar.DAY_OF_MONTH)) {
            increment =fromDate.getActualMaximum(Calendar.DAY_OF_MONTH);
        }
         System.out.println("increment"+increment);
// DAY CALCULATION
        if (increment != 0) {
            day = (toDate.get(Calendar.DAY_OF_MONTH) + increment) - fromDate.get(Calendar.DAY_OF_MONTH);
            increment = 1;
        } else {
            day = toDate.get(Calendar.DAY_OF_MONTH) - fromDate.get(Calendar.DAY_OF_MONTH);
        }

// MONTH CALCULATION
        if ((fromDate.get(Calendar.MONTH) + increment) > toDate.get(Calendar.MONTH)) {
            month = (toDate.get(Calendar.MONTH) + 12) - (fromDate.get(Calendar.MONTH) + increment);
            increment = 1;
        } else {
            month = (toDate.get(Calendar.MONTH)) - (fromDate.get(Calendar.MONTH) + increment);
            increment = 0;
        }

// YEAR CALCULATION
        year = toDate.get(Calendar.YEAR) - (fromDate.get(Calendar.YEAR) + increment);
     return   year+"\tYears\t\t"+month+"\tMonths\t\t"+day+"\tDays";
    }

    public static void main(String[] args) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(1999,01,8);
       /*  Calendar calendar1 = Calendar.getInstance();
        calendar1.set(2012,01,23);*/
        System.out.println(getDateDifferenceInDDMMYYYY(calendar.getTime(),new Date()));
    }

Answer 2

Joda Time 有一个可以使用的时间概念Interval，例如：

Interval interval = new Interval(oldDate.getTime(), newDate.getTime());

然后使用Period 对象，例如：

Period period = interval.toPeriod().normalizedStandard(PeriodType.yearMonthDay());

PeriodFormatter formatter = new PeriodFormatterBuilder()
            .appendYears()
            .appendSuffix(" year ", " years ")
            .appendSeparator(" and ")
            .appendMonths()
            .appendSuffix(" month ", " months ")
            .appendSeparator(" and ")
            .appendDays()
            .appendSuffix(" day ", " days ")
            .toFormatter();
System.out.println(formatter.print(period));

您将能够轻松打印您的年月差异。

您可能在发布问题时更改了某些内容，因为要修复您的代码（请注意，我没有测试您的代码是否适用于各种范围），您只需要正确初始化 Calendar 对象，反之亦然无效的选择检查：

Calendar c1 = Calendar.getInstance();
Calendar c2 = Calendar.getInstance();
if (oldDate.compareTo(newDate) < 0) {
    c2.setTime(newDate);
    c1.setTime(oldDate);
} else {
    System.out.println("invalid");
    return "Invalid selection";
}

Answer 3

tl;博士

Period.between( 
    LocalDate.of( 2017 , Month.JANUARY , 23 ) , 
    LocalDate.of( 2017 , Month.MARCH , 27 ) 
)

呼叫：

.getYears()
.getMonths()
.getDays()

避免使用旧的日期时间类

您正在使用麻烦的旧日期时间类，现在是遗留的，被 java.time 类所取代。

使用 java.time

LocalDate 类表示没有时间和时区的仅日期值。

时区对于确定日期至关重要。对于任何给定的时刻，日期在全球范围内因区域而异。例如，Paris France 中午夜过后几分钟是新的一天，而 Montréal Québec 中仍然是“昨天”。

以continent/region 的格式指定proper time zone name，例如America/Montreal、Africa/Casablanca 或Pacific/Auckland。切勿使用 3-4 个字母的缩写，例如 EST 或 IST，因为它们不是真正的时区，没有标准化，甚至不是唯一的 (!)。

ZoneId z = ZoneId.of( "America/Montreal" );
LocalDate today = LocalDate.now( z );

tod​​ay.toString(): 2017-05-05

对于我们的示例，我们创建另一个 LocalDate。

LocalDate earlier = today.minusMonths( 2 ).minusWeeks( 3 ).minusDays( 2 ) ;

earlier.toString(): 2017-02-10

要以年-月-日为粒度表示与时间轴无关的时间跨度，请使用 Period 类。

Period p = Period.between( earlier , today ) ;
int years = p.getYears();
int months = p.getMonths();
int days = p.getDays();

见this code run live at IdeOne.com。

ISO 8601

ISO 8601 标准定义了日期时间值的文本表示格式。对于年-月-日的持续时间，模式为PnYnMnDTnHnMnS，其中P 标志着开始，T 将年-月-日部分与小时-分钟-秒部分分开。

java.time 类在解析/生成字符串时默认使用标准格式。 Period 类在其 toString 方法中生成此特定模式。

String output = p.toString() ;

p.toString(): P2M25D

Answer 4

假设您有Date date1, date2，并且它们在date1>date2 的位置初始化。

long diff = date1.getTime() - date2.getTime(); //this is going to give you the difference in milliseconds

Date result = new Date(diff);
Format frmt = new SimpleDateFormat("yy MM dd HH:mm:ss");
return frmt.format(result).toString();//or if you want system.out.println(...);

Answer 5

    long diff = today.getTimeInMillis() - birth.getTimeInMillis();


    // Calculate difference in seconds
    long Seconds = diff / 1000;

    // Calculate difference in minutes
    long Minutes = diff / (60 * 1000);

    // Calculate difference in hours
    long Hours = diff / (60 * 60 * 1000);

    // Calculate difference in days
    long Days = diff / (24 * 60 * 60 * 1000);

    long Months = diff / (24 * 60 * 60 * 12 * 1000);

    //lblTsec, lblTmint, lblthours,lblTdays;
    System.out.println("Seconds : " + Seconds + "");
    System.out.println("Minutes : " + Minutes + "");
    System.out.println("Hours : " + Hours + "");
    System.out.println("Days : " + Days + "");

Answer 6

public static long[] differenceBetweenDates(Date fromDate, Date toDate) {
    Calendar startDate = Calendar.getInstance();
    startDate.setTime(fromDate);
    long years = 0;
    long months = 0;
    long days = 0;
    Calendar endDate = Calendar.getInstance();
    endDate.setTime(toDate);
    Calendar tmpdate = Calendar.getInstance();
    tmpdate.setTime(startDate.getTime());

    tmpdate.add(Calendar.YEAR, 1);
    while (tmpdate.compareTo(endDate) <= 0) {
        startDate.add(Calendar.YEAR, 1);
        tmpdate.add(Calendar.YEAR, 1);
        years++;
    }
    tmpdate.setTime(startDate.getTime());
    tmpdate.add(Calendar.MONTH, 1);
    while (tmpdate.compareTo(endDate) <= 0) {
        startDate.add(Calendar.MONTH, 1);
        tmpdate.add(Calendar.MONTH, 1);
        months++;
    }
    tmpdate.setTime(startDate.getTime());
    tmpdate.add(Calendar.DATE, 1);
    while (tmpdate.compareTo(endDate) <= 0) {
        startDate.add(Calendar.DATE, 1);
        tmpdate.add(Calendar.DATE, 1);
        days++;
    }
    return new long[]{days, months, years};
}

Answer 7

你可以简单地计算两个日期之间的差异毫秒并除以秒、分钟、小时、天和月

假设你想获得年份之间的差异，试试这个，

public int findDiff(Date fromDate, Date toDate) {

    if(fromDate == null || toDate == null) {
        return -1;
    }

    long diff = toDate.getTime() - fromDate.getTime();

    int diffInYears = (int) (diff / (60 * 60 * 1000 * 24 * 30.41666666 * 12));
    return diffInYears;
}

假设您希望月份之间的差异从分隔符中删除 12（表示月份）。同样你可以得到天，小时，分钟..