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

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Here is the source code for de.dhke.projects.cutil.collections.immutable.ImmutableEntrySet.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.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.apache.commons.collections15.Transformer;
import org.apache.commons.collections15.keyvalue.DefaultMapEntry;

/**
 *
 * @author Peter Wullinger <java@dhke.de>
 */
public class ImmutableEntrySet<K, V> implements Set<Map.Entry<K, V>>, IDecorator<Set<Map.Entry<K, V>>> {
    private final Set<Map.Entry<K, V>> _backEntrySet;
    private final Transformer<Map.Entry<K, V>, Map.Entry<K, V>> _entryTransformer;
    private final Transformer<K, K> _keyTransformer;
    private final Transformer<V, V> _valueTransformer;

    protected ImmutableEntrySet(final Set<Map.Entry<K, V>> backEntrySet, final Transformer<K, K> keyTransformer,
            final Transformer<V, V> valueTransformer) {
        _backEntrySet = backEntrySet;
        _keyTransformer = keyTransformer;
        _valueTransformer = valueTransformer;
        _entryTransformer = new EntryTransformer();
    }

    public static <K, V> ImmutableEntrySet<K, V> decorate(final Set<Map.Entry<K, V>> backEntrySet) {
        return new ImmutableEntrySet<>(backEntrySet, null, null);
    }

    public static <K, V> ImmutableEntrySet<K, V> decorate(final Set<Map.Entry<K, V>> backEntrySet,
            final Transformer<V, V> valueTransformer) {
        return new ImmutableEntrySet<>(backEntrySet, null, valueTransformer);
    }

    public static <K, V> ImmutableEntrySet<K, V> decorate(final Set<Map.Entry<K, V>> backEntrySet,
            final Transformer<K, K> keyTransformer, final Transformer<V, V> valueTransformer) {
        return new ImmutableEntrySet<>(backEntrySet, keyTransformer, valueTransformer);
    }

    @Override
    public Set<Entry<K, V>> getDecoratee() {
        return _backEntrySet;
    }

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

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

    @Override
    public boolean contains(Object o) {
        return _backEntrySet.contains(o);
    }

    @Override
    public Iterator<Entry<K, V>> iterator() {
        return ImmutableIterator.decorate(_backEntrySet.iterator(), _entryTransformer);
    }

    @Override
    public Object[] toArray() {
        return _backEntrySet.toArray();
    }

    @Override
    public <T> T[] toArray(T[] a) {
        return _backEntrySet.toArray(a);
    }

    @Override
    public boolean add(Entry<K, V> e) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public boolean remove(Object o) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public boolean containsAll(Collection<?> c) {
        return _backEntrySet.containsAll(c);
    }

    @Override
    public boolean addAll(Collection<? extends Entry<K, V>> c) {
        throw new UnsupportedOperationException("Cannot modify ImmutableMultiMapEntrySet.");
    }

    @Override
    public boolean retainAll(Collection<?> c) {
        throw new UnsupportedOperationException("Cannot modify ImmutableMultiMapEntrySet.");
    }

    @Override
    public boolean removeAll(Collection<?> c) {
        throw new UnsupportedOperationException("Cannot modify ImmutableMultiMapEntrySet.");
    }

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

    private final class EntryTransformer implements Transformer<Map.Entry<K, V>, Map.Entry<K, V>> {
        @Override
        public Entry<K, V> transform(Entry<K, V> input) {
            K key;
            if (_keyTransformer != null)
                key = _keyTransformer.transform(input.getKey());
            else
                key = input.getKey();

            V value;
            if (_valueTransformer != null)
                value = _valueTransformer.transform(input.getValue());
            else
                value = input.getValue();

            return new DefaultMapEntry<>(key, value);
        }

    }

}