- /*
- * 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>
- * This class is Serializable from Commons Collections 3.1.
- *
- * @since Commons Collections 3.0
- * @version $Revision: 1.14 $ $Date: 2004/06/07 22:14:42 $
- *
- * @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);
- }
-
- }