org.apache.commons.collections.set.UnmodifiableSortedSet Maven / Gradle / Ivy
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/*
* 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.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Collection;
import java.util.Iterator;
import java.util.SortedSet;
import org.apache.commons.collections.Unmodifiable;
import org.apache.commons.collections.iterators.UnmodifiableIterator;
/**
* Decorates another SortedSet
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 UnmodifiableSortedSet
extends AbstractSortedSetDecorator
implements Unmodifiable, Serializable {
/** Serialization version */
private static final long serialVersionUID = -725356885467962424L;
/**
* 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 SortedSet decorate(SortedSet set) {
if (set instanceof Unmodifiable) {
return set;
}
return new UnmodifiableSortedSet(set);
}
//-----------------------------------------------------------------------
/**
* Write the collection out using a custom routine.
*
* @param out the output stream
* @throws IOException
*/
private void writeObject(ObjectOutputStream out) throws IOException {
out.defaultWriteObject();
out.writeObject(collection);
}
/**
* Read the collection in using a custom routine.
*
* @param in the input stream
* @throws IOException
* @throws ClassNotFoundException
*/
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
collection = (Collection) in.readObject();
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* @param set the set to decorate, must not be null
* @throws IllegalArgumentException if set is null
*/
private UnmodifiableSortedSet(SortedSet 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();
}
//-----------------------------------------------------------------------
public SortedSet subSet(Object fromElement, Object toElement) {
SortedSet sub = getSortedSet().subSet(fromElement, toElement);
return new UnmodifiableSortedSet(sub);
}
public SortedSet headSet(Object toElement) {
SortedSet sub = getSortedSet().headSet(toElement);
return new UnmodifiableSortedSet(sub);
}
public SortedSet tailSet(Object fromElement) {
SortedSet sub = getSortedSet().tailSet(fromElement);
return new UnmodifiableSortedSet(sub);
}
}