001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one or more
003     *  contributor license agreements.  See the NOTICE file distributed with
004     *  this work for additional information regarding copyright ownership.
005     *  The ASF licenses this file to You under the Apache License, Version 2.0
006     *  (the "License"); you may not use this file except in compliance with
007     *  the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     *  Unless required by applicable law or agreed to in writing, software
012     *  distributed under the License is distributed on an "AS IS" BASIS,
013     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     *  See the License for the specific language governing permissions and
015     *  limitations under the License.
016     */
017    package org.apache.commons.collections.set;
018    
019    import java.util.SortedSet;
020    
021    import org.apache.commons.collections.functors.InstanceofPredicate;
022    
023    /**
024     * Decorates another <code>SortedSet</code> to validate that elements
025     * added are of a specific type.
026     * <p>
027     * The validation of additions is performed via an instanceof test against 
028     * a specified <code>Class</code>. If an object cannot be added to the
029     * collection, an IllegalArgumentException is thrown.
030     *
031     * @since Commons Collections 3.0
032     * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
033     * 
034     * @author Stephen Colebourne
035     * @author Matthew Hawthorne
036     */
037    public class TypedSortedSet {
038    
039        /**
040         * Factory method to create a typed sorted set.
041         * <p>
042         * If there are any elements already in the set being decorated, they
043         * are validated.
044         * 
045         * @param set  the set to decorate, must not be null
046         * @param type  the type to allow into the collection, must not be null
047         * @throws IllegalArgumentException if set or type is null
048         * @throws IllegalArgumentException if the set contains invalid elements
049         */
050        public static SortedSet decorate(SortedSet set, Class type) {
051            return new PredicatedSortedSet(set, InstanceofPredicate.getInstance(type));
052        }
053        
054        /**
055         * Restrictive constructor.
056         */
057        protected TypedSortedSet() {
058        }
059    
060    }