org.apache.commons.collections.set.UnmodifiableSet Maven / Gradle / Ivy
/*
* 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.collections.set;
import java.util.Collection;
import java.util.Iterator;
import java.util.Set;
import org.apache.commons.collections.Unmodifiable;
import org.apache.commons.collections.iterators.UnmodifiableIterator;
/**
* Decorates another Set
to ensure it can't be altered.
*
* This class is Serializable from Commons Collections 3.1.
*
* @since Commons Collections 3.0
* @version $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
*
* @author Stephen Colebourne
*/
public final class UnmodifiableSet
extends AbstractSerializableSetDecorator
implements Unmodifiable {
/** Serialization version */
private static final long serialVersionUID = 6499119872185240161L;
/**
* Factory method to create an unmodifiable set.
*
* @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 UnmodifiableSet(set);
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* @param set the set to decorate, must not be null
* @throws IllegalArgumentException if set is null
*/
private UnmodifiableSet(Set set) {
super(set);
}
//-----------------------------------------------------------------------
public Iterator iterator() {
return UnmodifiableIterator.decorate(getCollection().iterator());
}
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();
}
}