org.apache.commons.collections4.bidimap.UnmodifiableOrderedBidiMap Maven / Gradle / Ivy
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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
*
* 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.collections4.bidimap;
import java.util.Map;
import java.util.Set;
import org.apache.commons.collections4.OrderedBidiMap;
import org.apache.commons.collections4.OrderedMapIterator;
import org.apache.commons.collections4.Unmodifiable;
import org.apache.commons.collections4.iterators.UnmodifiableOrderedMapIterator;
import org.apache.commons.collections4.map.UnmodifiableEntrySet;
import org.apache.commons.collections4.set.UnmodifiableSet;
/**
* Decorates another {@link OrderedBidiMap} to ensure it can't be altered.
*
* Attempts to modify it will result in an UnsupportedOperationException.
*
* @param the type of the keys in this map
* @param the type of the values in this map
* @since 3.0
*/
public final class UnmodifiableOrderedBidiMap
extends AbstractOrderedBidiMapDecorator implements Unmodifiable {
/** The inverse unmodifiable map */
private UnmodifiableOrderedBidiMap inverse;
/**
* Factory method to create an unmodifiable map.
*
* If the map passed in is already unmodifiable, it is returned.
*
* @param the key type
* @param the value type
* @param map the map to decorate, must not be null
* @return an unmodifiable OrderedBidiMap
* @throws NullPointerException if map is null
* @since 4.0
*/
public static OrderedBidiMap unmodifiableOrderedBidiMap(
final OrderedBidiMap extends K, ? extends V> map) {
if (map instanceof Unmodifiable) {
@SuppressWarnings("unchecked") // safe to upcast
final OrderedBidiMap tmpMap = (OrderedBidiMap) map;
return tmpMap;
}
return new UnmodifiableOrderedBidiMap<>(map);
}
//-----------------------------------------------------------------------
/**
* 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 UnmodifiableOrderedBidiMap(final OrderedBidiMap extends K, ? extends V> map) {
super((OrderedBidiMap) 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> entrySet() {
final Set> set = super.entrySet();
return UnmodifiableEntrySet.unmodifiableEntrySet(set);
}
@Override
public Set keySet() {
final Set set = super.keySet();
return UnmodifiableSet.unmodifiableSet(set);
}
@Override
public Set values() {
final Set set = super.values();
return UnmodifiableSet.unmodifiableSet(set);
}
//-----------------------------------------------------------------------
@Override
public K removeValue(final Object value) {
throw new UnsupportedOperationException();
}
@Override
public OrderedBidiMap inverseBidiMap() {
return inverseOrderedBidiMap();
}
//-----------------------------------------------------------------------
@Override
public OrderedMapIterator mapIterator() {
final OrderedMapIterator it = decorated().mapIterator();
return UnmodifiableOrderedMapIterator.unmodifiableOrderedMapIterator(it);
}
/**
* Gets an unmodifiable view of this map where the keys and values are reversed.
*
* @return an inverted unmodifiable bidirectional map
*/
public OrderedBidiMap inverseOrderedBidiMap() {
if (inverse == null) {
inverse = new UnmodifiableOrderedBidiMap<>(decorated().inverseBidiMap());
inverse.inverse = this;
}
return inverse;
}
}