/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
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package org.apache.commons.collections4.keyvalue;

import java.io.Serializable;
import java.util.Map;

import org.apache.commons.collections4.KeyValue;

A Map.Entry tied to a map underneath.

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:3.0
/** * A {@link java.util.Map.Entry 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 3.0 */
public class TiedMapEntry<K, V> implements Map.Entry<K, V>, KeyValue<K, V>, Serializable {
Serialization version
/** Serialization version */
private static final long serialVersionUID = -8453869361373831205L;
The map underlying the entry/iterator
/** The map underlying the entry/iterator */
private final Map<K, V> map;
The key
/** The key */
private final K key;
Constructs a new entry with the given Map and key.
Params:
  • map – the map
  • key – the key
/** * Constructs a new entry with the given Map and key. * * @param map the map * @param key the key */
public TiedMapEntry(final Map<K, V> map, final K key) { super(); this.map = map; this.key = key; } // Map.Entry interface //-------------------------------------------------------------------------
Gets the key of this entry
Returns:the key
/** * Gets the key of this entry * * @return the key */
@Override public K getKey() { return key; }
Gets the value of this entry direct from the map.
Returns:the value
/** * Gets the value of this entry direct from the map. * * @return the value */
@Override public V getValue() { return map.get(key); }
Sets the value associated with the key direct onto the map.
Params:
  • value – the new value
Throws:
Returns:the old value
/** * 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 */
@Override public V setValue(final V 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.

Implemented per API documentation of Entry.equals(Object)

Params:
  • obj – the object to compare to
Returns:true if equal key and value
/** * 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 */
@Override public boolean equals(final Object obj) { if (obj == this) { return true; } if (obj instanceof Map.Entry == false) { return false; } final Map.Entry<?,?> other = (Map.Entry<?,?>) obj; final 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.

Implemented per API documentation of Entry.hashCode()

Returns:a suitable hash code
/** * 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 */
@Override public int hashCode() { final Object value = getValue(); return (getKey() == null ? 0 : getKey().hashCode()) ^ (value == null ? 0 : value.hashCode()); }
Gets a string version of the entry.
Returns:entry as a string
/** * Gets a string version of the entry. * * @return entry as a string */
@Override public String toString() { return getKey() + "=" + getValue(); } }