Android Date Interval Get calculateDiffInDays(Date date1, Date date2)

Description

Calculates the difference between the given Date in days.

Parameter

Parameter	Description
date1	- Date object.
date2	- Date object.

Exception

Parameter	Description
NullPointerException	if any of the parameters is null.

Return

-time difference in long days.

Declaration

public static long calculateDiffInDays(Date date1, Date date2) 

Method Source Code

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;

public class Main{
    public static final long MILLIS_PER_HOUR = 60 * MILLIS_PER_MINUTE;
    /**/*from  ww w  .java  2 s.c o m*/
     * Calculates the difference between the given {@link Date} in days.
     * <br>
     * Internally calls {@link #calculateDiffInHours(Date, Date)}. 
     * @param date1 -{@link Date} object.
     * @param date2 -{@link Date} object.
     * @return -time difference in long days.
     * @throws NullPointerException if any of the parameters is null.
     */
    public static long calculateDiffInDays(Date date1, Date date2) {
        if (StringUtils.isNull(date1)) {
            throw new NullPointerException("date1 cannot be null");
        }
        if (StringUtils.isNull(date2)) {
            throw new NullPointerException("date2 cannot be null");
        }
        long differenceInDays = (calculateDiffInHours(date1, date2)) / 24;
        return differenceInDays;
    }
    /**
     * Calculates the difference between the given {@link Date} in hours.
     * <br>
     * Internally calls {@link #calculateDiffInMilliSeconds(Date, Date)}. 
     * @param date1 -{@link Date} object.
     * @param date2 -{@link Date} object.
     * @return -time difference in long hours.
     * @throws NullPointerException if any of the parameters is null.
     */
    public static long calculateDiffInHours(Date date1, Date date2) {
        if (StringUtils.isNull(date1)) {
            throw new NullPointerException("date1 cannot be null");
        }
        if (StringUtils.isNull(date2)) {
            throw new NullPointerException("date2 cannot be null");
        }
        long differenceInHours = (calculateDiffInMilliSeconds(date1, date2))
                / MILLIS_PER_HOUR;
        return differenceInHours;
    }
    /**
     * Calculates the difference between the given {@link Date} in milliseconds.
     * 
     * @param date1 -{@link Date} object.
     * @param date2 -{@link Date} object.
     * @return -time difference in long milliseconds.
     * @throws NullPointerException if any of the parameters is null.
     */
    public static long calculateDiffInMilliSeconds(Date date1, Date date2) {
        if (StringUtils.isNull(date1)) {
            throw new NullPointerException("date1 cannot be null");
        }
        if (StringUtils.isNull(date2)) {
            throw new NullPointerException("date2 cannot be null");
        }
        long milliseconds1 = date1.getTime();
        long milliseconds2 = date2.getTime();
        long differenceInMilliSeconds = milliseconds2 - milliseconds1;
        return differenceInMilliSeconds;
    }
}

Related

1. DaysBetween(Date beginDate, Date endDate)
2. calculateDiffInHours(Date date1, Date date2)
3. calculateDiffInMilliSeconds(Date date1, Date date2)
4. calculateDiffInMinutes(Date date1, Date date2)
5. dateDiff(String startTime, String endTime)