de.dhke.projects.cutil.collections.frozen.FrozenFlat3Set.java Source code

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Here is the source code for de.dhke.projects.cutil.collections.frozen.FrozenFlat3Set.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.frozen;

import de.dhke.projects.cutil.collections.set.Flat3Set;
import java.util.Collection;
import java.util.Iterator;
import org.apache.commons.collections15.SetUtils;

/**
 * A frozen set that uses {@link Flat3Set} 
 * as a backing set.
 *
 * @author Peter Wullinger <peter.wullinger@uni-bamberg.de>
 */
public class FrozenFlat3Set<T> extends Flat3Set<T> {
    private int _hashValue = 0;

    public FrozenFlat3Set(final Collection<? extends T> coll) {
        super(coll);
    }

    @Override
    public Iterator<T> iterator() {
        return FrozenIterator.decorate(super.iterator());
    }

    @Override
    public boolean add(T e) {
        throw new UnsupportedOperationException("Unable to modify FrozenSet");
    }

    @Override
    public boolean remove(Object o) {
        throw new UnsupportedOperationException("Unable to modify FrozenSet");
    }

    @Override
    public boolean addAll(Collection<? extends T> c) {
        throw new UnsupportedOperationException("Unable to modify FrozenSet");
    }

    @Override
    public boolean retainAll(Collection<?> c) {
        throw new UnsupportedOperationException("Unable to modify FrozenSet");
    }

    @Override
    public boolean removeAll(Collection<?> c) {
        throw new UnsupportedOperationException("Unable to modify FrozenSet");
    }

    @Override
    public void clear() {
        throw new UnsupportedOperationException("Unable to modify FrozenSet");
    }

    @Override
    public int hashCode() {
        if (_hashValue == 0)
            _hashValue = SetUtils.hashCodeForSet(this);
        return _hashValue;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        else if (obj instanceof Collection)
            return SetUtils.isEqualSet(this, (Collection<?>) obj);
        else
            return false;
    }

    @Override
    public String toString() {
        final StringBuffer sb = new StringBuffer(2 + size() * 3);
        sb.append("{");
        boolean first = true;
        for (T item : this) {
            if (first)
                first = false;
            else
                sb.append(", ");
            sb.append(item);
        }
        sb.append("}");
        return sb.toString();
    }

}