- /*
- * 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.io.Serializable;
- import java.util.Map;
-
- import org.apache.commons.collections.KeyValue;
-
- /**
- * A Map Entry tied to a map underneath.
- * <p>
- * This can be used to enable a map entry to make changes on the underlying
- * map, however this will probably mess up any iterators.
- *
- * @since Commons Collections 3.0
- * @version $Revision: 1.5 $ $Date: 2004/04/09 14:35:10 $
- *
- * @author Stephen Colebourne
- */
- public class TiedMapEntry implements Map.Entry, KeyValue, Serializable {
-
- /** Serialization version */
- private static final long serialVersionUID = -8453869361373831205L;
-
- /** The map underlying the entry/iterator */
- private final Map map;
- /** The key */
- private final Object key;
-
- /**
- * Constructs a new entry with the given Map and key.
- *
- * @param map the map
- * @param key the key
- */
- public TiedMapEntry(Map map, Object key) {
- super();
- this.map = map;
- this.key = key;
- }
-
- // Map.Entry interface
- //-------------------------------------------------------------------------
- /**
- * Gets the key of this entry
- *
- * @return the key
- */
- public Object getKey() {
- return key;
- }
-
- /**
- * Gets the value of this entry direct from the map.
- *
- * @return the value
- */
- public Object getValue() {
- return map.get(key);
- }
-
- /**
- * Sets the value associated with the key direct onto the map.
- *
- * @param value the new value
- * @return the old value
- * @throws IllegalArgumentException if the value is set to this map entry
- */
- public Object setValue(Object value) {
- if (value == this) {
- throw new IllegalArgumentException("Cannot set value to this map entry");
- }
- return map.put(key, value);
- }
-
- /**
- * 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;
- Object value = getValue();
- return
- (key == null ? other.getKey() == null : key.equals(other.getKey())) &&
- (value == null ? other.getValue() == null : value.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() {
- Object value = getValue();
- return (getKey() == null ? 0 : getKey().hashCode()) ^
- (value == null ? 0 : value.hashCode());
- }
-
- /**
- * Gets a string version of the entry.
- *
- * @return entry as a string
- */
- public String toString() {
- return getKey() + "=" + getValue();
- }
-
- }