Commons Collections example source code file (FixedSizeList.java)

This example Commons Collections source code file (FixedSizeList.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons Collections tags/keywords

abstractserializablelistdecorator, boundedcollection, collection, fixedsizelist, fixedsizelist, fixedsizelistiterator, iterator, list, list, listiterator, object, object, unsupportedoperationexception, unsupportedoperationexception, util

The Commons Collections FixedSizeList.java source code

/*
 *  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 <code>List to fix the size preventing add/remove.
 * <p>
 * The add, remove, clear and retain operations are unsupported.
 * The set method is allowed (as it doesn't change the list size).
 * <p>
 * This class is Serializable from Commons Collections 3.1.
 *
 * @since Commons Collections 3.0
 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (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();
    }

}