- /*
- * Copyright 2003-2004 The Apache Software Foundation
- *
- * Licensed 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.collections.map;
-
- import java.lang.reflect.Array;
- import java.util.Collection;
- import java.util.Iterator;
- import java.util.Map;
- import java.util.Set;
-
- import org.apache.commons.collections.Unmodifiable;
- import org.apache.commons.collections.iterators.AbstractIteratorDecorator;
- import org.apache.commons.collections.keyvalue.AbstractMapEntryDecorator;
- import org.apache.commons.collections.set.AbstractSetDecorator;
-
- /**
- * Decorates a map entry <code>Set</code> to ensure it can't be altered.
- *
- * @since Commons Collections 3.0
- * @version $Revision: 1.6 $ $Date: 2004/02/18 01:13:19 $
- *
- * @author Stephen Colebourne
- */
- public final class UnmodifiableEntrySet
- extends AbstractSetDecorator implements Unmodifiable {
-
- /**
- * Factory method to create an unmodifiable set of Map Entry objects.
- *
- * @param set the set to decorate, must not be null
- * @throws IllegalArgumentException if set is null
- */
- public static Set decorate(Set set) {
- if (set instanceof Unmodifiable) {
- return set;
- }
- return new UnmodifiableEntrySet(set);
- }
-
- //-----------------------------------------------------------------------
- /**
- * Constructor that wraps (not copies).
- *
- * @param set the set to decorate, must not be null
- * @throws IllegalArgumentException if set is null
- */
- private UnmodifiableEntrySet(Set set) {
- super(set);
- }
-
- //-----------------------------------------------------------------------
- public boolean add(Object object) {
- throw new UnsupportedOperationException();
- }
-
- public boolean addAll(Collection coll) {
- throw new UnsupportedOperationException();
- }
-
- public void clear() {
- throw new UnsupportedOperationException();
- }
-
- public boolean remove(Object object) {
- throw new UnsupportedOperationException();
- }
-
- public boolean removeAll(Collection coll) {
- throw new UnsupportedOperationException();
- }
-
- public boolean retainAll(Collection coll) {
- throw new UnsupportedOperationException();
- }
-
- //-----------------------------------------------------------------------
- public Iterator iterator() {
- return new UnmodifiableEntrySetIterator(collection.iterator());
- }
-
- public Object[] toArray() {
- Object[] array = collection.toArray();
- for (int i = 0; i < array.length; i++) {
- array[i] = new UnmodifiableEntry((Map.Entry) array[i]);
- }
- return array;
- }
-
- public Object[] toArray(Object array[]) {
- Object[] result = array;
- if (array.length > 0) {
- // we must create a new array to handle multi-threaded situations
- // where another thread could access data before we decorate it
- result = (Object[]) Array.newInstance(array.getClass().getComponentType(), 0);
- }
- result = collection.toArray(result);
- for (int i = 0; i < result.length; i++) {
- result[i] = new UnmodifiableEntry((Map.Entry) result[i]);
- }
-
- // check to see if result should be returned straight
- if (result.length > array.length) {
- return result;
- }
-
- // copy back into input array to fulfil the method contract
- System.arraycopy(result, 0, array, 0, result.length);
- if (array.length > result.length) {
- array[result.length] = null;
- }
- return array;
- }
-
- //-----------------------------------------------------------------------
- /**
- * Implementation of an entry set iterator.
- */
- final static class UnmodifiableEntrySetIterator extends AbstractIteratorDecorator {
-
- protected UnmodifiableEntrySetIterator(Iterator iterator) {
- super(iterator);
- }
-
- public Object next() {
- Map.Entry entry = (Map.Entry) iterator.next();
- return new UnmodifiableEntry(entry);
- }
-
- public void remove() {
- throw new UnsupportedOperationException();
- }
- }
-
- //-----------------------------------------------------------------------
- /**
- * Implementation of a map entry that is unmodifiable.
- */
- final static class UnmodifiableEntry extends AbstractMapEntryDecorator {
-
- protected UnmodifiableEntry(Map.Entry entry) {
- super(entry);
- }
-
- public Object setValue(Object obj) {
- throw new UnsupportedOperationException();
- }
- }
-
- }