- /*
- * 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.util.Comparator;
- import java.util.SortedMap;
-
- import org.apache.commons.collections.Factory;
- import org.apache.commons.collections.Transformer;
-
- /**
- * Decorates another <code>SortedMap</code> to create objects in the map on demand.
- * <p>
- * When the {@link #get(Object)} method is called with a key that does not
- * exist in the map, the factory is used to create the object. The created
- * object will be added to the map using the requested key.
- * <p>
- * For instance:
- * <pre>
- * Factory factory = new Factory() {
- * public Object create() {
- * return new Date();
- * }
- * }
- * SortedMap lazy = Lazy.sortedMap(new HashMap(), factory);
- * Object obj = lazy.get("NOW");
- * </pre>
- *
- * After the above code is executed, <code>obj</code> will contain
- * a new <code>Date</code> instance. Furthermore, that <code>Date</code>
- * instance is mapped to the "NOW" key in the map.
- * <p>
- * This class is Serializable from Commons Collections 3.1.
- *
- * @since Commons Collections 3.0
- * @version $Revision: 1.6 $ $Date: 2004/04/09 10:36:01 $
- *
- * @author Stephen Colebourne
- * @author Paul Jack
- */
- public class LazySortedMap
- extends LazyMap
- implements SortedMap {
-
- /** Serialization version */
- private static final long serialVersionUID = 2715322183617658933L;
-
- /**
- * Factory method to create a lazily instantiated sorted map.
- *
- * @param map the map to decorate, must not be null
- * @param factory the factory to use, must not be null
- * @throws IllegalArgumentException if map or factory is null
- */
- public static SortedMap decorate(SortedMap map, Factory factory) {
- return new LazySortedMap(map, factory);
- }
-
- /**
- * Factory method to create a lazily instantiated sorted map.
- *
- * @param map the map to decorate, must not be null
- * @param factory the factory to use, must not be null
- * @throws IllegalArgumentException if map or factory is null
- */
- public static SortedMap decorate(SortedMap map, Transformer factory) {
- return new LazySortedMap(map, factory);
- }
-
- //-----------------------------------------------------------------------
- /**
- * Constructor that wraps (not copies).
- *
- * @param map the map to decorate, must not be null
- * @param factory the factory to use, must not be null
- * @throws IllegalArgumentException if map or factory is null
- */
- protected LazySortedMap(SortedMap map, Factory factory) {
- super(map, factory);
- }
-
- /**
- * Constructor that wraps (not copies).
- *
- * @param map the map to decorate, must not be null
- * @param factory the factory to use, must not be null
- * @throws IllegalArgumentException if map or factory is null
- */
- protected LazySortedMap(SortedMap map, Transformer factory) {
- super(map, factory);
- }
-
- //-----------------------------------------------------------------------
- /**
- * Gets the map being decorated.
- *
- * @return the decorated map
- */
- protected SortedMap getSortedMap() {
- return (SortedMap) map;
- }
-
- //-----------------------------------------------------------------------
- public Object firstKey() {
- return getSortedMap().firstKey();
- }
-
- public Object lastKey() {
- return getSortedMap().lastKey();
- }
-
- public Comparator comparator() {
- return getSortedMap().comparator();
- }
-
- public SortedMap subMap(Object fromKey, Object toKey) {
- SortedMap map = getSortedMap().subMap(fromKey, toKey);
- return new LazySortedMap(map, factory);
- }
-
- public SortedMap headMap(Object toKey) {
- SortedMap map = getSortedMap().headMap(toKey);
- return new LazySortedMap(map, factory);
- }
-
- public SortedMap tailMap(Object fromKey) {
- SortedMap map = getSortedMap().tailMap(fromKey);
- return new LazySortedMap(map, factory);
- }
-
- }