org.apache.commons.collections.list.FixedSizeList 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.list;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import org.apache.commons.collections.BoundedCollection;
import org.apache.commons.collections.iterators.AbstractListIteratorDecorator;
import org.apache.commons.collections.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.
*
* @since Commons Collections 3.0
* @version $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
*
* @author Stephen Colebourne
* @author Paul Jack
*/
public class FixedSizeList
extends AbstractSerializableListDecorator
implements BoundedCollection {
/** Serialization version */
private static final long serialVersionUID = -2218010673611160319L;
/**
* Factory method to create a fixed size list.
*
* @param list the list to decorate, must not be null
* @throws IllegalArgumentException if list is null
*/
public static List decorate(List list) {
return new FixedSizeList(list);
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* @param list the list to decorate, must not be null
* @throws IllegalArgumentException if list is null
*/
protected FixedSizeList(List list) {
super(list);
}
//-----------------------------------------------------------------------
public boolean add(Object object) {
throw new UnsupportedOperationException("List is fixed size");
}
public void add(int index, Object object) {
throw new UnsupportedOperationException("List is fixed size");
}
public boolean addAll(Collection coll) {
throw new UnsupportedOperationException("List is fixed size");
}
public boolean addAll(int index, Collection coll) {
throw new UnsupportedOperationException("List is fixed size");
}
public void clear() {
throw new UnsupportedOperationException("List is fixed size");
}
public Object get(int index) {
return getList().get(index);
}
public int indexOf(Object object) {
return getList().indexOf(object);
}
public Iterator iterator() {
return UnmodifiableIterator.decorate(getCollection().iterator());
}
public int lastIndexOf(Object object) {
return getList().lastIndexOf(object);
}
public ListIterator listIterator() {
return new FixedSizeListIterator(getList().listIterator(0));
}
public ListIterator listIterator(int index) {
return new FixedSizeListIterator(getList().listIterator(index));
}
public Object remove(int index) {
throw new UnsupportedOperationException("List is fixed size");
}
public boolean remove(Object object) {
throw new UnsupportedOperationException("List is fixed size");
}
public boolean removeAll(Collection coll) {
throw new UnsupportedOperationException("List is fixed size");
}
public boolean retainAll(Collection coll) {
throw new UnsupportedOperationException("List is fixed size");
}
public Object set(int index, Object object) {
return getList().set(index, object);
}
public List subList(int fromIndex, int toIndex) {
List sub = getList().subList(fromIndex, toIndex);
return new FixedSizeList(sub);
}
/**
* List iterator that only permits changes via set()
*/
static class FixedSizeListIterator extends AbstractListIteratorDecorator {
protected FixedSizeListIterator(ListIterator iterator) {
super(iterator);
}
public void remove() {
throw new UnsupportedOperationException("List is fixed size");
}
public void add(Object object) {
throw new UnsupportedOperationException("List is fixed size");
}
}
public boolean isFull() {
return true;
}
public int maxSize() {
return size();
}
}