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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.collections4.list;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import org.apache.commons.collections4.BoundedCollection;
import org.apache.commons.collections4.iterators.AbstractListIteratorDecorator;
import org.apache.commons.collections4.iterators.UnmodifiableIterator;
/**
* Decorates another List
to fix the size preventing add/remove.
*
* The add, remove, clear and retain operations are unsupported.
* The set method is allowed (as it doesn't change the list size).
*
* This class is Serializable from Commons Collections 3.1.
*
* @param the type of elements in this collection
* @since 3.0
*/
public class FixedSizeList
extends AbstractSerializableListDecorator
implements BoundedCollection {
/** Serialization version */
private static final long serialVersionUID = -2218010673611160319L;
/**
* Factory method to create a fixed size list.
*
* @param the type of the elements in the list
* @param list the list to decorate, must not be null
* @return a new fixed size list
* @throws NullPointerException if list is null
* @since 4.0
*/
public static FixedSizeList fixedSizeList(final List list) {
return new FixedSizeList<>(list);
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* @param list the list to decorate, must not be null
* @throws NullPointerException if list is null
*/
protected FixedSizeList(final List list) {
super(list);
}
//-----------------------------------------------------------------------
@Override
public boolean add(final E object) {
throw new UnsupportedOperationException("List is fixed size");
}
@Override
public void add(final int index, final E object) {
throw new UnsupportedOperationException("List is fixed size");
}
@Override
public boolean addAll(final Collection coll) {
throw new UnsupportedOperationException("List is fixed size");
}
@Override
public boolean addAll(final int index, final Collection coll) {
throw new UnsupportedOperationException("List is fixed size");
}
@Override
public void clear() {
throw new UnsupportedOperationException("List is fixed size");
}
@Override
public E get(final int index) {
return decorated().get(index);
}
@Override
public int indexOf(final Object object) {
return decorated().indexOf(object);
}
@Override
public Iterator iterator() {
return UnmodifiableIterator.unmodifiableIterator(decorated().iterator());
}
@Override
public int lastIndexOf(final Object object) {
return decorated().lastIndexOf(object);
}
@Override
public ListIterator listIterator() {
return new FixedSizeListIterator(decorated().listIterator(0));
}
@Override
public ListIterator listIterator(final int index) {
return new FixedSizeListIterator(decorated().listIterator(index));
}
@Override
public E remove(final int index) {
throw new UnsupportedOperationException("List is fixed size");
}
@Override
public boolean remove(final Object object) {
throw new UnsupportedOperationException("List is fixed size");
}
@Override
public boolean removeAll(final Collection coll) {
throw new UnsupportedOperationException("List is fixed size");
}
@Override
public boolean retainAll(final Collection coll) {
throw new UnsupportedOperationException("List is fixed size");
}
@Override
public E set(final int index, final E object) {
return decorated().set(index, object);
}
@Override
public List subList(final int fromIndex, final int toIndex) {
final List sub = decorated().subList(fromIndex, toIndex);
return new FixedSizeList<>(sub);
}
/**
* List iterator that only permits changes via set()
*/
private class FixedSizeListIterator extends AbstractListIteratorDecorator {
protected FixedSizeListIterator(final ListIterator iterator) {
super(iterator);
}
@Override
public void remove() {
throw new UnsupportedOperationException("List is fixed size");
}
@Override
public void add(final Object object) {
throw new UnsupportedOperationException("List is fixed size");
}
}
@Override
public boolean isFull() {
return true;
}
@Override
public int maxSize() {
return size();
}
}