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    1   /*
    2    * $HeadURL: https://svn.apache.org/repos/asf/jakarta/httpcomponents/oac.hc3x/tags/HTTPCLIENT_3_1/src/java/org/apache/commons/httpclient/util/LangUtils.java $
    3    * $Revision: 480424 $
    4    * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
    5    *
    6    * ====================================================================
    7    *
    8    *  Licensed to the Apache Software Foundation (ASF) under one or more
    9    *  contributor license agreements.  See the NOTICE file distributed with
    10   *  this work for additional information regarding copyright ownership.
    11   *  The ASF licenses this file to You under the Apache License, Version 2.0
    12   *  (the "License"); you may not use this file except in compliance with
    13   *  the License.  You may obtain a copy of the License at
    14   *
    15   *      http://www.apache.org/licenses/LICENSE-2.0
    16   *
    17   *  Unless required by applicable law or agreed to in writing, software
    18   *  distributed under the License is distributed on an "AS IS" BASIS,
    19   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    20   *  See the License for the specific language governing permissions and
    21   *  limitations under the License.
    22   * ====================================================================
    23   *
    24   * This software consists of voluntary contributions made by many
    25   * individuals on behalf of the Apache Software Foundation.  For more
    26   * information on the Apache Software Foundation, please see
    27   * <http://www.apache.org/>.
    28   *
    29   */
    30
    31  package org.apache.commons.httpclient.util;
    32
    33  /**
    34   * A set of utility methods to help produce consistent Object#equals(Object) and
    35   * Object#hashCode methods.
    36   *
    37   * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
    38   *
    39   * @since 3.0
    40   */
    41  public class LangUtils {
    42
    43      public static final int HASH_SEED = 17;
    44      public static final int HASH_OFFSET = 37;
    45
    46      private LangUtils() {
    47          super();
    48      }
    49
    50      public static int hashCode(final int seed, final int hashcode) {
    51          return seed * HASH_OFFSET + hashcode;
    52      }
    53
    54      public static int hashCode(final int seed, final Object obj) {
    55          return hashCode(seed, obj != null ? obj.hashCode() : 0);
    56      }
    57
    58      public static int hashCode(final int seed, final boolean b) {
    59          return hashCode(seed, b ? 1 : 0);
    60      }
    61
    62      public static boolean equals(final Object obj1, final Object obj2) {
    63          return obj1 == null ? obj2 == null : obj1.equals(obj2);
    64      }
    65
    66  }