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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.collections4.map;
import java.util.Comparator;
import java.util.Map;
import java.util.SortedMap;
import org.apache.commons.collections4.Transformer;
/**
* Decorates another SortedMap to transform objects that are added.
*
* The Map put methods and Map.Entry setValue method are affected by this class.
* Thus objects must be removed or searched for using their transformed form.
* For example, if the transformation converts Strings to Integers, you must
* use the Integer form to remove objects.
*
*
* Note that TransformedSortedMap is not synchronized and is not thread-safe.
* 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#synchronizedSortedMap}. This class may throw
* exceptions when accessed by concurrent threads without synchronization.
*
*
* This class is Serializable from Commons Collections 3.1.
*
*
* @param the type of the keys in this map
* @param the type of the values in this map
* @since 3.0
*/
public class TransformedSortedMap
extends TransformedMap
implements SortedMap {
/** Serialization version */
private static final long serialVersionUID = -8751771676410385778L;
/**
* Factory method to create a transforming sorted map.
*
* If there are any elements already in the map being decorated, they are NOT transformed.
* Contrast this with {@link #transformedSortedMap(SortedMap, Transformer, Transformer)}.
*
* @param the key type
* @param the value type
* @param map the map to decorate, must not be null
* @param keyTransformer the predicate to validate the keys, null means no transformation
* @param valueTransformer the predicate to validate to values, null means no transformation
* @return a new transformed sorted map
* @throws NullPointerException if the map is null
* @since 4.0
*/
public static TransformedSortedMap transformingSortedMap(final SortedMap map,
final Transformer keyTransformer,
final Transformer valueTransformer) {
return new TransformedSortedMap<>(map, keyTransformer, valueTransformer);
}
/**
* Factory method to create a transforming sorted map that will transform
* existing contents of the specified map.
*
* If there are any elements already in the map being decorated, they
* will be transformed by this method.
* Contrast this with {@link #transformingSortedMap(SortedMap, Transformer, Transformer)}.
*
* @param the key type
* @param the value type
* @param map the map to decorate, must not be null
* @param keyTransformer the transformer to use for key conversion, null means no transformation
* @param valueTransformer the transformer to use for value conversion, null means no transformation
* @return a new transformed sorted map
* @throws NullPointerException if map is null
* @since 4.0
*/
public static TransformedSortedMap transformedSortedMap(final SortedMap map,
final Transformer keyTransformer,
final Transformer valueTransformer) {
final TransformedSortedMap decorated =
new TransformedSortedMap<>(map, keyTransformer, valueTransformer);
if (map.size() > 0) {
final Map transformed = decorated.transformMap(map);
decorated.clear();
decorated.decorated().putAll(transformed); // avoids double transformation
}
return decorated;
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* If there are any elements already in the collection being decorated, they
* are NOT transformed.
*
* @param map the map to decorate, must not be null
* @param keyTransformer the predicate to validate the keys, null means no transformation
* @param valueTransformer the predicate to validate to values, null means no transformation
* @throws NullPointerException if the map is null
*/
protected TransformedSortedMap(final SortedMap map,
final Transformer keyTransformer,
final Transformer valueTransformer) {
super(map, keyTransformer, valueTransformer);
}
//-----------------------------------------------------------------------
/**
* Gets the map being decorated.
*
* @return the decorated map
*/
protected SortedMap getSortedMap() {
return (SortedMap) map;
}
//-----------------------------------------------------------------------
@Override
public K firstKey() {
return getSortedMap().firstKey();
}
@Override
public K lastKey() {
return getSortedMap().lastKey();
}
@Override
public Comparator comparator() {
return getSortedMap().comparator();
}
@Override
public SortedMap subMap(final K fromKey, final K toKey) {
final SortedMap map = getSortedMap().subMap(fromKey, toKey);
return new TransformedSortedMap<>(map, keyTransformer, valueTransformer);
}
@Override
public SortedMap headMap(final K toKey) {
final SortedMap map = getSortedMap().headMap(toKey);
return new TransformedSortedMap<>(map, keyTransformer, valueTransformer);
}
@Override
public SortedMap tailMap(final K fromKey) {
final SortedMap map = getSortedMap().tailMap(fromKey);
return new TransformedSortedMap<>(map, keyTransformer, valueTransformer);
}
}