Java Calendar Compare isSameInstant(Calendar cal1, Calendar cal2)

Description

Checks if two calendar objects represent the same instant in time.

This method compares the long millisecond time of the two objects.

License

Open Source License

Parameter

Parameter	Description
cal1	the first calendar, not altered, not null
cal2	the second calendar, not altered, not null

Exception

Parameter	Description
IllegalArgumentException	if either date is <code>null</code>

Return

true if they represent the same millisecond instant

Declaration

public static boolean isSameInstant(Calendar cal1, Calendar cal2)

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright (c) 2011 MadRobot.//from   w  ww . j a  v a2 s.co m
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v2.1
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * 
 * Contributors:
 *  Elton Kent - initial API and implementation
 ******************************************************************************/

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

public class Main {
    /**
     * <p>Checks if two calendar objects represent the same instant in time.</p>
     *
     * <p>This method compares the long millisecond time of the two objects.</p>
     * 
     * @param cal1  the first calendar, not altered, not null
     * @param cal2  the second calendar, not altered, not null
     * @return true if they represent the same millisecond instant
     * @throws IllegalArgumentException if either date is <code>null</code>
     * @since 2.1
     */
    public static boolean isSameInstant(Calendar cal1, Calendar cal2) {
        if (cal1 == null || cal2 == null) {
            throw new IllegalArgumentException("The date must not be null");
        }
        return cal1.getTime().getTime() == cal2.getTime().getTime();
    }

    /**
     * <p>Checks if two date objects represent the same instant in time.</p>
     *
     * <p>This method compares the long millisecond time of the two objects.</p>
     * 
     * @param date1  the first date, not altered, not null
     * @param date2  the second date, not altered, not null
     * @return true if they represent the same millisecond instant
     * @throws IllegalArgumentException if either date is <code>null</code>
     * @since 2.1
     */
    public static boolean isSameInstant(Date date1, Date date2) {
        if (date1 == null || date2 == null) {
            throw new IllegalArgumentException("The date must not be null");
        }
        return date1.getTime() == date2.getTime();
    }
}