org.apache.commons.collections.bag.TypedBag 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 org.apache.commons.collections.Bag;
import org.apache.commons.collections.functors.InstanceofPredicate;
/**
* Decorates another Bag
to validate that elements added
* are of a specific type.
*
* The validation of additions is performed via an instanceof test against
* a specified Class
. If an object cannot be added to the
* collection, an IllegalArgumentException is thrown.
*
* @since Commons Collections 3.0
* @version $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
*
* @author Stephen Colebourne
* @author Matthew Hawthorne
*/
public class TypedBag {
/**
* Factory method to create a typed bag.
*
* If there are any elements already in the bag being decorated, they
* are validated.
*
* @param bag the bag to decorate, must not be null
* @param type the type to allow into the bag, must not be null
* @return a new typed Bag
* @throws IllegalArgumentException if bag or type is null
* @throws IllegalArgumentException if the bag contains invalid elements
*/
public static Bag decorate(Bag bag, Class type) {
return new PredicatedBag(bag, InstanceofPredicate.getInstance(type));
}
/**
* Restrictive constructor.
*/
protected TypedBag() {
super();
}
}