deep Hash Code for Map - Java Collection Framework

Java examples for Collection Framework:Map

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Description

deep Hash Code for Map

Demo Code

/**// w  ww .j  a v a2 s  . c om
 * (c) 2009-2014 Peter Wullinger
 *
 * $Id$
 *
 * Use, modification and restribution of this file are covered by the
 * terms of the Artistic License 2.0.
 *
 * You should have received a copy of the license terms in a file named
 * "LICENSE" together with this software package.
 *
 * Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT
 * HOLDER AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES. THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
 * A PARTICULAR PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED TO THE
 * EXTENT PERMITTED BY YOUR LOCAL LAW. UNLESS REQUIRED BY LAW, NO
 * COPYRIGHT HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT
 * OF THE USE OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 **/
//package com.java2s;

import java.util.Map;

public class Main {
    public static <K, V> int deepHashCode(Map.Entry<K, V> entry) {
        return entry.getKey().hashCode() * entry.getValue().hashCode();
    }

    public static <K, V> int deepHashCode(Map<K, V> m) {
        int hashCode = 91;
        for (Map.Entry<K, V> entry : m.entrySet()) {
            hashCode += 13 * deepHashCode(entry);
        }
        return hashCode;
    }
}

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