Java Object Hash deepHashCode(final Object object)

Description

Returns a hash code for the specified object, which may be an array.

License

Open Source License

Parameter

Parameter	Description
object	The object to compute hash code. May be null .

Return

The hash code of the given object.

Declaration

public static int deepHashCode(final Object object) 

Method Source Code

//package com.java2s;
/*/*from w w  w .  jav a  2  s. com*/
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2001-2008, Open Source Geospatial Foundation (OSGeo)
 *
 *    This library is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License as published by the Free Software Foundation;
 *    version 2.1 of the License.
 *
 *    This library 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
 *    Lesser General Public License for more details.
 */

import java.util.Arrays;

public class Main {
    /**
     * Returns a hash code for the specified object, which may be an array.
     * This method returns one of the following values:
     * <p>
     * <ul>
     *   <li>If the supplied object is {@code null}, then this method returns 0.</li>
     *   <li>Otherwise if the object is an array of objects, then
     *       {@link Arrays#deepHashCode(Object[])} is invoked.</li>
     *   <li>Otherwise if the object is an array of primitive type, then the corresponding
     *       {@link Arrays#hashCode(double[]) Arrays.hashCode(...)} method is invoked.</li>
     *   <li>Otherwise {@link Object#hashCode()} is invoked.<li>
     * </ul>
     * <p>
     * This method should be invoked <strong>only</strong> if the object type is declared
     * exactly as {@code Object}, not as some subtype like {@code Object[]}, {@code String} or
     * {@code float[]}. In the later cases, use the appropriate {@link Arrays} method instead.
     *
     * @param object The object to compute hash code. May be {@code null}.
     * @return The hash code of the given object.
     */
    public static int deepHashCode(final Object object) {
        if (object == null) {
            return 0;
        }
        if (object instanceof Object[]) {
            return Arrays.deepHashCode((Object[]) object);
        }
        if (object instanceof double[]) {
            return Arrays.hashCode((double[]) object);
        }
        if (object instanceof float[]) {
            return Arrays.hashCode((float[]) object);
        }
        if (object instanceof long[]) {
            return Arrays.hashCode((long[]) object);
        }
        if (object instanceof int[]) {
            return Arrays.hashCode((int[]) object);
        }
        if (object instanceof short[]) {
            return Arrays.hashCode((short[]) object);
        }
        if (object instanceof byte[]) {
            return Arrays.hashCode((byte[]) object);
        }
        if (object instanceof char[]) {
            return Arrays.hashCode((char[]) object);
        }
        if (object instanceof boolean[]) {
            return Arrays.hashCode((boolean[]) object);
        }
        return object.hashCode();
    }
}

Related

1. combineHashesOrdered(Object... objs)
2. deepHashCode(Object o)
3. getIdentityAsHex(Object object)
4. hash(Object o)
5. hash(Object... objects)