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 * 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
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 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
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package org.apache.commons.collections4.bidimap;

import java.util.Map;
import java.util.Set;

import org.apache.commons.collections4.BidiMap;
import org.apache.commons.collections4.MapIterator;
import org.apache.commons.collections4.Unmodifiable;
import org.apache.commons.collections4.iterators.UnmodifiableMapIterator;
import org.apache.commons.collections4.map.UnmodifiableEntrySet;
import org.apache.commons.collections4.set.UnmodifiableSet;

Decorates another BidiMap to ensure it can't be altered.

Attempts to modify it will result in an UnsupportedOperationException.

Type parameters:
  • <K> – the type of the keys in this map
  • <V> – the type of the values in this map
Since:3.0
/** * Decorates another {@link BidiMap} to ensure it can't be altered. * <p> * Attempts to modify it will result in an UnsupportedOperationException. * </p> * * @param <K> the type of the keys in this map * @param <V> the type of the values in this map * @since 3.0 */
public final class UnmodifiableBidiMap<K, V> extends AbstractBidiMapDecorator<K, V> implements Unmodifiable {
The inverse unmodifiable map
/** The inverse unmodifiable map */
private UnmodifiableBidiMap<V, K> inverse;
Factory method to create an unmodifiable map.

If the map passed in is already unmodifiable, it is returned.

Params:
  • map – the map to decorate, must not be null
Type parameters:
  • <K> – the key type
  • <V> – the value type
Throws:
Returns:an unmodifiable BidiMap
Since:4.0
/** * Factory method to create an unmodifiable map. * <p> * If the map passed in is already unmodifiable, it is returned. * * @param <K> the key type * @param <V> the value type * @param map the map to decorate, must not be null * @return an unmodifiable BidiMap * @throws NullPointerException if map is null * @since 4.0 */
public static <K, V> BidiMap<K, V> unmodifiableBidiMap(final BidiMap<? extends K, ? extends V> map) { if (map instanceof Unmodifiable) { @SuppressWarnings("unchecked") // safe to upcast final BidiMap<K, V> tmpMap = (BidiMap<K, V>) map; return tmpMap; } return new UnmodifiableBidiMap<>(map); } //-----------------------------------------------------------------------
Constructor that wraps (not copies).
Params:
  • map – the map to decorate, must not be null
Throws:
/** * Constructor that wraps (not copies). * * @param map the map to decorate, must not be null * @throws NullPointerException if map is null */
@SuppressWarnings("unchecked") // safe to upcast private UnmodifiableBidiMap(final BidiMap<? extends K, ? extends V> map) { super((BidiMap<K, V>) map); } //----------------------------------------------------------------------- @Override public void clear() { throw new UnsupportedOperationException(); } @Override public V put(final K key, final V value) { throw new UnsupportedOperationException(); } @Override public void putAll(final Map<? extends K, ? extends V> mapToCopy) { throw new UnsupportedOperationException(); } @Override public V remove(final Object key) { throw new UnsupportedOperationException(); } @Override public Set<Map.Entry<K, V>> entrySet() { final Set<Map.Entry<K, V>> set = super.entrySet(); return UnmodifiableEntrySet.unmodifiableEntrySet(set); } @Override public Set<K> keySet() { final Set<K> set = super.keySet(); return UnmodifiableSet.unmodifiableSet(set); } @Override public Set<V> values() { final Set<V> set = super.values(); return UnmodifiableSet.unmodifiableSet(set); } //----------------------------------------------------------------------- @Override public K removeValue(final Object value) { throw new UnsupportedOperationException(); } @Override public MapIterator<K, V> mapIterator() { final MapIterator<K, V> it = decorated().mapIterator(); return UnmodifiableMapIterator.unmodifiableMapIterator(it); } @Override public synchronized BidiMap<V, K> inverseBidiMap() { if (inverse == null) { inverse = new UnmodifiableBidiMap<>(decorated().inverseBidiMap()); inverse.inverse = this; } return inverse; } }