org.apache.commons.collections.bag.TransformedBag Maven / Gradle / Ivy
/*
* 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.collections.bag;
import java.util.Set;
import org.apache.commons.collections.Bag;
import org.apache.commons.collections.Transformer;
import org.apache.commons.collections.collection.TransformedCollection;
import org.apache.commons.collections.set.TransformedSet;
/**
* Decorates another Bag 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.
*
* This class is Serializable from Commons Collections 3.1.
*
* @since Commons Collections 3.0
* @version $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
*
* @author Stephen Colebourne
*/
public class TransformedBag
extends TransformedCollection implements Bag {
/** Serialization version */
private static final long serialVersionUID = 5421170911299074185L;
/**
* Factory method to create a transforming bag.
*
* If there are any elements already in the bag being decorated, they
* are NOT transformed.
*
* @param bag the bag to decorate, must not be null
* @param transformer the transformer to use for conversion, must not be null
* @return a new transformed Bag
* @throws IllegalArgumentException if bag or transformer is null
*/
public static Bag decorate(Bag bag, Transformer transformer) {
return new TransformedBag(bag, transformer);
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* If there are any elements already in the bag being decorated, they
* are NOT transformed.
*
* @param bag the bag to decorate, must not be null
* @param transformer the transformer to use for conversion, must not be null
* @throws IllegalArgumentException if bag or transformer is null
*/
protected TransformedBag(Bag bag, Transformer transformer) {
super(bag, transformer);
}
/**
* Gets the decorated bag.
*
* @return the decorated bag
*/
protected Bag getBag() {
return (Bag) collection;
}
//-----------------------------------------------------------------------
public int getCount(Object object) {
return getBag().getCount(object);
}
public boolean remove(Object object, int nCopies) {
return getBag().remove(object, nCopies);
}
//-----------------------------------------------------------------------
public boolean add(Object object, int nCopies) {
object = transform(object);
return getBag().add(object, nCopies);
}
public Set uniqueSet() {
Set set = getBag().uniqueSet();
return TransformedSet.decorate(set, transformer);
}
}