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 */ 017package org.apache.camel.converter; 018 019import java.util.ArrayList; 020import java.util.Arrays; 021import java.util.Collection; 022import java.util.HashMap; 023import java.util.HashSet; 024import java.util.Hashtable; 025import java.util.Iterator; 026import java.util.LinkedList; 027import java.util.List; 028import java.util.Map; 029import java.util.Properties; 030import java.util.Set; 031 032import org.apache.camel.Converter; 033 034/** 035 * Some core java.util Collection based 036 * <a href="http://camel.apache.org/type-converter.html">Type Converters</a> 037 * 038 * @version 039 */ 040@Converter 041public final class CollectionConverter { 042 043 /** 044 * Utility classes should not have a public constructor. 045 */ 046 private CollectionConverter() { 047 } 048 049 /** 050 * Converts a collection to an array 051 */ 052 @Converter 053 public static Object[] toArray(Collection<?> value) { 054 return value.toArray(); 055 } 056 057 /** 058 * Converts an array to a collection 059 */ 060 @Converter 061 public static List<Object> 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 <T> List<T> toList(Collection<T> collection) { 070 return new ArrayList<T>(collection); 071 } 072 073 /** 074 * Converts an {@link Iterator} to a {@link ArrayList} 075 */ 076 @Converter 077 public static <T> ArrayList<T> toArrayList(Iterator<T> it) { 078 ArrayList<T> list = new ArrayList<T>(); 079 while (it.hasNext()) { 080 list.add(it.next()); 081 } 082 return list; 083 } 084 085 @Converter 086 public static Set<Object> toSet(Object[] array) { 087 Set<Object> answer = new HashSet<Object>(); 088 answer.addAll(Arrays.asList(array)); 089 return answer; 090 } 091 092 @Converter 093 public static <T> Set<T> toSet(Collection<T> collection) { 094 return new HashSet<T>(collection); 095 } 096 097 @Converter 098 public static <K, V> Set<Map.Entry<K, V>> toSet(Map<K, V> map) { 099 return map.entrySet(); 100 } 101 102 @Converter 103 public static Properties toProperties(Map<Object, Object> map) { 104 Properties answer = new Properties(); 105 answer.putAll(map); 106 return answer; 107 } 108 109 @Converter 110 public static <K, V> Hashtable<K, V> toHashtable(Map<? extends K, ? extends V> map) { 111 return new Hashtable<K, V>(map); 112 } 113 114 @Converter 115 public static <K, V> HashMap<K, V> toHashMap(Map<? extends K, ? extends V> map) { 116 return new HashMap<K, V>(map); 117 } 118 119 /** 120 * Converts an {@link Iterable} into a {@link List} 121 */ 122 @Converter 123 public static <T> List<T> toList(Iterable<T> iterable) { 124 if (iterable instanceof List) { 125 return (List<T>) iterable; 126 } 127 List<T> result = new LinkedList<T>(); 128 for (T value : iterable) { 129 result.add(value); 130 } 131 return result; 132 } 133}