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.map; 018 019 import java.util.Map; 020 021 import org.apache.commons.collections.functors.InstanceofPredicate; 022 023 /** 024 * Decorates another <code>Map</code> to validate that elements added 025 * 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 * <p> 031 * <strong>Note that TypedMap is not synchronized and is not thread-safe.</strong> 032 * If you wish to use this map from multiple threads concurrently, you must use 033 * appropriate synchronization. The simplest approach is to wrap this map 034 * using {@link java.util.Collections#synchronizedMap(Map)}. This class may throw 035 * exceptions when accessed by concurrent threads without synchronization. 036 * <p> 037 * The returned implementation is Serializable from Commons Collections 3.1. 038 * 039 * @since Commons Collections 3.0 040 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $ 041 * 042 * @author Stephen Colebourne 043 * @author Matthew Hawthorne 044 */ 045 public class TypedMap { 046 047 /** 048 * Factory method to create a typed map. 049 * <p> 050 * If there are any elements already in the map being decorated, they 051 * are validated. 052 * 053 * @param map the map to decorate, must not be null 054 * @param keyType the type to allow as keys, must not be null 055 * @param valueType the type to allow as values, must not be null 056 * @throws IllegalArgumentException if list or type is null 057 * @throws IllegalArgumentException if the list contains invalid elements 058 */ 059 public static Map decorate(Map map, Class keyType, Class valueType) { 060 return new PredicatedMap( 061 map, 062 InstanceofPredicate.getInstance(keyType), 063 InstanceofPredicate.getInstance(valueType) 064 ); 065 } 066 067 /** 068 * Restrictive constructor. 069 */ 070 protected TypedMap() { 071 } 072 073 }