org.apache.commons.collections4.set.TransformedNavigableSet Maven / Gradle / Ivy
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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.set;
import java.util.Iterator;
import java.util.NavigableSet;
import org.apache.commons.collections4.Transformer;
/**
* Decorates another NavigableSet to transform objects that are added.
*
* The add methods 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.
*
* @param the type of the elements in this set
* @since 4.1
*/
public class TransformedNavigableSet extends TransformedSortedSet implements NavigableSet {
/** Serialization version */
private static final long serialVersionUID = 20150528L;
/**
* Factory method to create a transforming navigable set.
*
* If there are any elements already in the set being decorated, they
* are NOT transformed.
* Contrast this with {@link #transformedNavigableSet(NavigableSet, Transformer)}.
*
* @param the element type
* @param set the set to decorate, must not be null
* @param transformer the transformer to use for conversion, must not be null
* @return a new transformed {@link NavigableSet}
* @throws NullPointerException if set or transformer is null
*/
public static TransformedNavigableSet transformingNavigableSet(final NavigableSet set,
final Transformer transformer) {
return new TransformedNavigableSet<>(set, transformer);
}
/**
* Factory method to create a transforming navigable set that will transform
* existing contents of the specified navigable set.
*
* If there are any elements already in the set being decorated, they
* will be transformed by this method.
* Contrast this with {@link #transformingNavigableSet(NavigableSet, Transformer)}.
*
* @param the element type
* @param set the set to decorate, must not be null
* @param transformer the transformer to use for conversion, must not be null
* @return a new transformed {@link NavigableSet}
* @throws NullPointerException if set or transformer is null
*/
public static TransformedNavigableSet transformedNavigableSet(final NavigableSet set,
final Transformer transformer) {
final TransformedNavigableSet decorated = new TransformedNavigableSet<>(set, transformer);
if (set.size() > 0) {
@SuppressWarnings("unchecked") // set is type E
final E[] values = (E[]) set.toArray(); // NOPMD - false positive for generics
set.clear();
for (final E value : values) {
decorated.decorated().add(transformer.transform(value));
}
}
return decorated;
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* If there are any elements already in the set being decorated, they
* are NOT transformed.
*
* @param set the set to decorate, must not be null
* @param transformer the transformer to use for conversion, must not be null
* @throws NullPointerException if set or transformer is null
*/
protected TransformedNavigableSet(final NavigableSet set,
final Transformer transformer) {
super(set, transformer);
}
/**
* Gets the decorated navigable set.
*
* @return the decorated navigable set
*/
@Override
protected NavigableSet decorated() {
return (NavigableSet) super.decorated();
}
//-----------------------------------------------------------------------
@Override
public E lower(final E e) {
return decorated().lower(e);
}
@Override
public E floor(final E e) {
return decorated().floor(e);
}
@Override
public E ceiling(final E e) {
return decorated().ceiling(e);
}
@Override
public E higher(final E e) {
return decorated().higher(e);
}
@Override
public E pollFirst() {
return decorated().pollFirst();
}
@Override
public E pollLast() {
return decorated().pollLast();
}
@Override
public NavigableSet descendingSet() {
return transformingNavigableSet(decorated().descendingSet(), transformer);
}
@Override
public Iterator descendingIterator() {
return decorated().descendingIterator();
}
@Override
public NavigableSet subSet(final E fromElement, final boolean fromInclusive, final E toElement,
final boolean toInclusive) {
final NavigableSet sub = decorated().subSet(fromElement, fromInclusive, toElement, toInclusive);
return transformingNavigableSet(sub, transformer);
}
@Override
public NavigableSet headSet(final E toElement, final boolean inclusive) {
final NavigableSet head = decorated().headSet(toElement, inclusive);
return transformingNavigableSet(head, transformer);
}
@Override
public NavigableSet tailSet(final E fromElement, final boolean inclusive) {
final NavigableSet tail = decorated().tailSet(fromElement, inclusive);
return transformingNavigableSet(tail, transformer);
}
}