| /* |
| * Copyright 2003-2006 The Apache Software Foundation |
| * |
| * 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 org.apache.commons.collections.keyvalue; |
| |
| import java.util.Map; |
| |
| /** |
| * Abstract Pair class to assist with creating correct |
| * {@link java.util.Map.Entry Map.Entry} implementations. |
| * |
| * @since Commons Collections 3.0 |
| * @version $Revision: 1.1 $ $Date: 2009/05/27 22:16:29 $ |
| * |
| * @author James Strachan |
| * @author Michael A. Smith |
| * @author Neil O'Toole |
| * @author Stephen Colebourne |
| */ |
| public abstract class AbstractMapEntry extends AbstractKeyValue implements Map.Entry { |
| |
| /** |
| * Constructs a new entry with the given key and given value. |
| * |
| * @param key the key for the entry, may be null |
| * @param value the value for the entry, may be null |
| */ |
| protected AbstractMapEntry(Object key, Object value) { |
| super(key, value); |
| } |
| |
| // Map.Entry interface |
| //------------------------------------------------------------------------- |
| /** |
| * Sets the value stored in this <code>Map.Entry</code>. |
| * <p> |
| * This <code>Map.Entry</code> is not connected to a Map, so only the |
| * local data is changed. |
| * |
| * @param value the new value |
| * @return the previous value |
| */ |
| public Object setValue(Object value) { |
| Object answer = this.value; |
| this.value = value; |
| return answer; |
| } |
| |
| /** |
| * Compares this <code>Map.Entry</code> with another <code>Map.Entry</code>. |
| * <p> |
| * Implemented per API documentation of {@link java.util.Map.Entry#equals(Object)} |
| * |
| * @param obj the object to compare to |
| * @return true if equal key and value |
| */ |
| public boolean equals(Object obj) { |
| if (obj == this) { |
| return true; |
| } |
| if (obj instanceof Map.Entry == false) { |
| return false; |
| } |
| Map.Entry other = (Map.Entry) obj; |
| return |
| (getKey() == null ? other.getKey() == null : getKey().equals(other.getKey())) && |
| (getValue() == null ? other.getValue() == null : getValue().equals(other.getValue())); |
| } |
| |
| /** |
| * Gets a hashCode compatible with the equals method. |
| * <p> |
| * Implemented per API documentation of {@link java.util.Map.Entry#hashCode()} |
| * |
| * @return a suitable hash code |
| */ |
| public int hashCode() { |
| return (getKey() == null ? 0 : getKey().hashCode()) ^ |
| (getValue() == null ? 0 : getValue().hashCode()); |
| } |
| |
| } |