user/super/com/google/gwt/emul/java/util/HashMap.java

/*
 * Copyright 2008 Google Inc.
 * 
 * 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.
 */
package java.util;

import java.io.Serializable;

/**
 * Implementation of Map interface based on a hash table. <a
 * href="http://java.sun.com/j2se/1.5.0/docs/api/java/util/HashMap.html">[Sun
 * docs]</a>
 * 
 * @param <K> key type
 * @param <V> value type
 */
public class HashMap<K, V> extends AbstractHashMap<K, V> implements Cloneable,
    Serializable {

  public HashMap() {
  }

  public HashMap(int ignored) {
    // This implementation of HashMap has no need of initial capacities.
    this(ignored, 0);
  }

  public HashMap(int ignored, float alsoIgnored) {
    // This implementation of HashMap has no need of load factors or capacities.
    if (ignored < 0 || alsoIgnored < 0) {
      throw new IllegalArgumentException(
          "initial capacity was negative or load factor was non-positive");
    }
  }

  public HashMap(Map<? extends K, ? extends V> toBeCopied) {
    super(toBeCopied);
  }

  @Override
  public Object clone() {
    return new HashMap<K, V>(this);
  }

  @Override
  protected boolean equals(Object value1, Object value2) {
    return Utility.equalsWithNullCheck(value1, value2);
  }

  @Override
  protected int getHashCode(Object key) {
    return key.hashCode();
  }
}