Java Calendar Day getAge(Calendar dateOfBirth, Calendar onThisDay)

Description

This method will calculate the age of the person on the given date.

License

Open Source License

Declaration

public static Integer getAge(Calendar dateOfBirth, Calendar onThisDay) 

Method Source Code

//package com.java2s;
/**// w w  w.j av a 2s .  c o m
 * Copyright (c) 2001-2002. Department of Family Medicine, McMaster University. All Rights Reserved.
 * This software is published under the GPL GNU General Public License.
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version. 
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * This software was written for the
 * Department of Family Medicine
 * McMaster University
 * Hamilton
 * Ontario, Canada
 */

import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

public class Main {
    /**
     * This method will calculate the age of the person on the given date.
     */
    public static Integer getAge(Calendar dateOfBirth, Calendar onThisDay) {
        return (yearDifference(dateOfBirth, onThisDay));
    }

    /**
     * date2-date1
     * 
     * if either are null, it returns null.
     */
    public static Integer yearDifference(Date date1, Date date2) {
        if (date1 == null || date2 == null)
            return (null);

        Calendar cal1 = new GregorianCalendar();
        cal1.setTime(date1);

        Calendar cal2 = new GregorianCalendar();
        cal2.setTime(date2);

        return (yearDifference(cal1, cal2));
    }

    /**
     * date2-date1
     * 
     * if either are null, it returns null.
     */
    public static Integer yearDifference(Calendar date1, Calendar date2) {
        if (date1 == null || date2 == null)
            return (null);

        int yearDiff = date2.get(Calendar.YEAR) - date1.get(Calendar.YEAR);

        if (date2.get(Calendar.MONTH) > date1.get(Calendar.MONTH))
            yearDiff--;
        else if (date2.get(Calendar.MONTH) == date1.get(Calendar.MONTH)
                && date2.get(Calendar.DAY_OF_MONTH) < date1.get(Calendar.DAY_OF_MONTH))
            yearDiff--;

        return (yearDiff);
    }
}

Related

1. daysSinceTheJesus(Calendar cal)
2. dayStart(Calendar date)
3. dayStart(final Calendar cal)
4. decreaseByDay(final Calendar calendar)
5. endOfDay(Calendar calendar)
6. getBeginDay(Calendar cal)
7. getCanonicalDay(Calendar cal)
8. getCanonicalDayFrom(Calendar day, int daysFrom)
9. getCleanDay(Calendar c)