| /* |
| * Copyright 2003-2004 The Apache Software Foundation |
| * |
| * Licensed 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.map; |
| |
| import java.io.IOException; |
| import java.io.ObjectInputStream; |
| import java.io.ObjectOutputStream; |
| import java.io.Serializable; |
| import java.util.Iterator; |
| import java.util.Map; |
| |
| import org.apache.commons.collections.Predicate; |
| |
| /** |
| * Decorates another <code>Map</code> to validate that additions |
| * match a specified predicate. |
| * <p> |
| * This map exists to provide validation for the decorated map. |
| * It is normally created to decorate an empty map. |
| * If an object cannot be added to the map, an IllegalArgumentException is thrown. |
| * <p> |
| * One usage would be to ensure that no null keys are added to the map. |
| * <pre>Map map = PredicatedSet.decorate(new HashMap(), NotNullPredicate.INSTANCE, null);</pre> |
| * <p> |
| * <strong>Note that PredicatedMap is not synchronized and is not thread-safe.</strong> |
| * If you wish to use this map from multiple threads concurrently, you must use |
| * appropriate synchronization. The simplest approach is to wrap this map |
| * using {@link java.util.Collections#synchronizedMap(Map)}. This class may throw |
| * exceptions when accessed by concurrent threads without synchronization. |
| * <p> |
| * This class is Serializable from Commons Collections 3.1. |
| * |
| * @since Commons Collections 3.0 |
| * @version $Revision: 1.1 $ $Date: 2009/05/27 22:16:30 $ |
| * |
| * @author Stephen Colebourne |
| * @author Paul Jack |
| */ |
| public class PredicatedMap |
| extends AbstractInputCheckedMapDecorator |
| implements Serializable { |
| |
| /** Serialization version */ |
| private static final long serialVersionUID = 7412622456128415156L; |
| |
| /** The key predicate to use */ |
| protected final Predicate keyPredicate; |
| /** The value predicate to use */ |
| protected final Predicate valuePredicate; |
| |
| /** |
| * Factory method to create a predicated (validating) map. |
| * <p> |
| * If there are any elements already in the list being decorated, they |
| * are validated. |
| * |
| * @param map the map to decorate, must not be null |
| * @param keyPredicate the predicate to validate the keys, null means no check |
| * @param valuePredicate the predicate to validate to values, null means no check |
| * @throws IllegalArgumentException if the map is null |
| */ |
| public static Map decorate(Map map, Predicate keyPredicate, Predicate valuePredicate) { |
| return new PredicatedMap(map, keyPredicate, valuePredicate); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Constructor that wraps (not copies). |
| * |
| * @param map the map to decorate, must not be null |
| * @param keyPredicate the predicate to validate the keys, null means no check |
| * @param valuePredicate the predicate to validate to values, null means no check |
| * @throws IllegalArgumentException if the map is null |
| */ |
| protected PredicatedMap(Map map, Predicate keyPredicate, Predicate valuePredicate) { |
| super(map); |
| this.keyPredicate = keyPredicate; |
| this.valuePredicate = valuePredicate; |
| |
| Iterator it = map.entrySet().iterator(); |
| while (it.hasNext()) { |
| Map.Entry entry = (Map.Entry) it.next(); |
| Object key = entry.getKey(); |
| Object value = entry.getValue(); |
| validate(key, value); |
| } |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Write the map out using a custom routine. |
| * |
| * @param out the output stream |
| * @throws IOException |
| * @since Commons Collections 3.1 |
| */ |
| private void writeObject(ObjectOutputStream out) throws IOException { |
| out.defaultWriteObject(); |
| out.writeObject(map); |
| } |
| |
| /** |
| * Read the map in using a custom routine. |
| * |
| * @param in the input stream |
| * @throws IOException |
| * @throws ClassNotFoundException |
| * @since Commons Collections 3.1 |
| */ |
| private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException { |
| in.defaultReadObject(); |
| map = (Map) in.readObject(); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Validates a key value pair. |
| * |
| * @param key the key to validate |
| * @param value the value to validate |
| * @throws IllegalArgumentException if invalid |
| */ |
| protected void validate(Object key, Object value) { |
| if (keyPredicate != null && keyPredicate.evaluate(key) == false) { |
| throw new IllegalArgumentException("Cannot add key - Predicate rejected it"); |
| } |
| if (valuePredicate != null && valuePredicate.evaluate(value) == false) { |
| throw new IllegalArgumentException("Cannot add value - Predicate rejected it"); |
| } |
| } |
| |
| /** |
| * Override to validate an object set into the map via <code>setValue</code>. |
| * |
| * @param value the value to validate |
| * @throws IllegalArgumentException if invalid |
| * @since Commons Collections 3.1 |
| */ |
| protected Object checkSetValue(Object value) { |
| if (valuePredicate.evaluate(value) == false) { |
| throw new IllegalArgumentException("Cannot set value - Predicate rejected it"); |
| } |
| return value; |
| } |
| |
| /** |
| * Override to only return true when there is a value transformer. |
| * |
| * @return true if a value predicate is in use |
| * @since Commons Collections 3.1 |
| */ |
| protected boolean isSetValueChecking() { |
| return (valuePredicate != null); |
| } |
| |
| //----------------------------------------------------------------------- |
| public Object put(Object key, Object value) { |
| validate(key, value); |
| return map.put(key, value); |
| } |
| |
| public void putAll(Map mapToCopy) { |
| Iterator it = mapToCopy.entrySet().iterator(); |
| while (it.hasNext()) { |
| Map.Entry entry = (Map.Entry) it.next(); |
| Object key = entry.getKey(); |
| Object value = entry.getValue(); |
| validate(key, value); |
| } |
| map.putAll(mapToCopy); |
| } |
| |
| } |