Java Year Get calcDifferenceAsYears(Calendar aBaseDate, Calendar aTargetDate)

Description

calc Difference As Years

License

Apache License

Declaration

public static Integer calcDifferenceAsYears(Calendar aBaseDate, Calendar aTargetDate) throws ParseException 

Method Source Code

//package com.java2s;
/*/* ww  w  .j  a  va 2 s .  c  om*/
 * Copyright 2012 Hiromasa Horiguchi ( The University of Tokyo )
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.text.ParseException;
import java.util.Calendar;

public class Main {

    public static Integer calcDifferenceAsYears(Calendar aBaseDate, Calendar aTargetDate) throws ParseException {
        if (aBaseDate.getTimeInMillis() > aTargetDate.getTimeInMillis()) {
            return -1 * calcDifferenceAsYearsPrivate(aTargetDate, aBaseDate);
        } else {
            return calcDifferenceAsYearsPrivate(aBaseDate, aTargetDate);
        }
    }

    private static int calcDifferenceAsYearsPrivate(Calendar aBaseDate, Calendar aTargetDate) {
        int tBaseDateMonth = aBaseDate.get(Calendar.MONTH);
        int tTargetDateMonth = aTargetDate.get(Calendar.MONTH);
        return aTargetDate.get(Calendar.YEAR) - aBaseDate.get(Calendar.YEAR)
                - (tBaseDateMonth > tTargetDateMonth || (tBaseDateMonth == tTargetDateMonth
                        && aBaseDate.get(Calendar.DATE) > aTargetDate.get(Calendar.DATE)) ? 1 : 0);
    }
}

Related

1. currentYear()
2. currentYear()
3. currentYearStr()
4. getBeforeYear()