de.dhke.projects.cutil.collections.immutable.ImmutableMap.java Source code

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Here is the source code for de.dhke.projects.cutil.collections.immutable.ImmutableMap.java

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/**
 * (c) 2009-2014 Peter Wullinger
 *
 * $Id$
 *
 * Use, modification and restribution of this file are covered by the
 * terms of the Artistic License 2.0.
 *
 * You should have received a copy of the license terms in a file named
 * "LICENSE" together with this software package.
 *
 * Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT
 * HOLDER AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES. THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
 * A PARTICULAR PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED TO THE
 * EXTENT PERMITTED BY YOUR LOCAL LAW. UNLESS REQUIRED BY LAW, NO
 * COPYRIGHT HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT
 * OF THE USE OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 **/
package de.dhke.projects.cutil.collections.immutable;

import de.dhke.projects.cutil.IDecorator;
import java.util.Collection;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.apache.commons.collections15.Transformer;

/**
 *
 * @author Peter Wullinger <java@dhke.de>
 */
public class ImmutableMap<K, V> implements Map<K, V>, IDecorator<Map<K, V>> {
    private final Map<K, V> _backMap;
    private final Transformer<K, K> _keyTransformer;
    private final Transformer<V, V> _valueTransformer;

    private ImmutableMap(final Map<K, V> backMap, final Transformer<K, K> keyTransformer,
            final Transformer<V, V> valueTransformer) {
        _backMap = backMap;
        _keyTransformer = keyTransformer;
        _valueTransformer = valueTransformer;
    }

    public static <K, V> ImmutableMap<K, V> decorate(final Map<K, V> backMap) {
        return new ImmutableMap<>(backMap, null, null);
    }

    public static <K, V> ImmutableMap<K, V> decorate(final Map<K, V> backMap,
            final Transformer<V, V> valueTransformer) {
        return new ImmutableMap<>(backMap, null, valueTransformer);
    }

    public static <K, V> ImmutableMap<K, V> decorate(final Map<K, V> backMap,
            final Transformer<K, K> keyTransformer, final Transformer<V, V> valueTransformer) {
        return new ImmutableMap<>(backMap, keyTransformer, valueTransformer);
    }

    @Override
    public Map<K, V> getDecoratee() {
        return _backMap;
    }

    @Override
    public int size() {
        return _backMap.size();
    }

    @Override
    public boolean isEmpty() {
        return _backMap.isEmpty();
    }

    @Override
    public boolean containsKey(Object key) {
        return _backMap.containsKey(key);
    }

    @Override
    public boolean containsValue(Object value) {
        return _backMap.containsValue(value);
    }

    @Override
    public V get(Object key) {
        return _backMap.get(key);
    }

    @Override
    public V put(K key, V value) {
        throw new UnsupportedOperationException("Cannot modify ImmutableCollectionMap.");
    }

    @Override
    public V remove(Object key) {
        throw new UnsupportedOperationException("Cannot modify ImmutableCollectionMap.");
    }

    @Override
    public void putAll(Map<? extends K, ? extends V> m) {
        throw new UnsupportedOperationException("Cannot modify ImmutableCollectionMap.");
    }

    @Override
    public void clear() {
        throw new UnsupportedOperationException("Cannot modify ImmutableCollectionMap.");
    }

    @Override
    public Set<K> keySet() {
        return GenericImmutableSet.decorate(_backMap.keySet(), _keyTransformer);
    }

    @Override
    public Collection<V> values() {
        return GenericImmutableCollection.decorate(_backMap.values(), _valueTransformer);
    }

    @Override
    public Set<Entry<K, V>> entrySet() {
        return ImmutableEntrySet.decorate(_backMap.entrySet(), _keyTransformer, _valueTransformer);
    }

}