- /*
- * Copyright 2003-2004 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 Map Entry implementations.
- *
- * @since Commons Collections 3.0
- * @version $Revision: 1.4 $ $Date: 2004/02/18 01:00:08 $
- *
- * @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 Map Entry.
- * <p>
- * This Map Entry 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 Map Entry with another Map Entry.
- * <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());
- }
-
- }