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.camel.converter;
018    
019    import java.util.ArrayList;
020    import java.util.Arrays;
021    import java.util.Collection;
022    import java.util.HashMap;
023    import java.util.HashSet;
024    import java.util.Hashtable;
025    import java.util.List;
026    import java.util.Map;
027    import java.util.Properties;
028    import java.util.Set;
029    
030    import org.apache.camel.Converter;
031    
032    /**
033     * Some core java.util Collection based
034     * <a href="http://activemq.apache.org/camel/type-converter.html">Type Converters</a>
035     *
036     * @version $Revision: 36321 $
037     */
038    @Converter
039    public final class CollectionConverter {
040        /**
041         * Utility classes should not have a public constructor.
042         */
043        private CollectionConverter() {
044        }
045    
046        /**
047         * Converts a collection to an array
048         */
049        @Converter
050        public static Object[] toArray(Collection value) {
051            if (value == null) {
052                return null;
053            }
054            return value.toArray();
055        }
056    
057        /**
058         * Converts an array to a collection
059         */
060        @Converter
061        public static List toList(Object[] array) {
062            return Arrays.asList(array);
063        }
064    
065        /**
066         * Converts a collection to a List if it is not already
067         */
068        @Converter
069        public static List toList(Collection collection) {
070            return new ArrayList(collection);
071        }
072    
073        @Converter
074        public static Set toSet(Object[] array) {
075            Set answer = new HashSet();
076            for (Object element : array) {
077                answer.add(element);
078            }
079            return answer;
080        }
081    
082        @Converter
083        public static Set toSet(Collection collection) {
084            return new HashSet(collection);
085        }
086    
087        @Converter
088        public static Set toSet(Map map) {
089            return map.entrySet();
090        }
091    
092        @Converter
093        public static Properties toProperties(Map map) {
094            Properties answer = new Properties();
095            answer.putAll(map);
096            return answer;
097        }
098    
099        @Converter
100        public static Hashtable toHashtable(Map map) {
101            return new Hashtable(map);
102        }
103    
104        @Converter
105        public static HashMap toHashMap(Map map) {
106            return new HashMap(map);
107        }
108    }