/*
* 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.buffer;
import org.apache.commons.collections.Buffer;
import org.apache.commons.collections.Predicate;
import org.apache.commons.collections.collection.PredicatedCollection;
/**
* Decorates another <code>Buffer</code> to validate that additions
* match a specified predicate.
* <p>
* This buffer exists to provide validation for the decorated buffer.
* It is normally created to decorate an empty buffer.
* If an object cannot be added to the buffer, an IllegalArgumentException is thrown.
* <p>
* One usage would be to ensure that no null entries are added to the buffer.
* <pre>Buffer buffer = PredicatedBuffer.decorate(new UnboundedFifoBuffer(), NotNullPredicate.INSTANCE);</pre>
* <p>
* This class is Serializable from Commons Collections 3.1.
*
* @since Commons Collections 3.0
* @version $Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
*
* @author Stephen Colebourne
* @author Paul Jack
*/
public class PredicatedBuffer extends PredicatedCollection implements Buffer {
/** Serialization version */
private static final long serialVersionUID = 2307609000539943581L;
/**
* Factory method to create a predicated (validating) buffer.
* <p>
* If there are any elements already in the buffer being decorated, they
* are validated.
*
* @param buffer the buffer to decorate, must not be null
* @param predicate the predicate to use for validation, must not be null
* @return a new predicated Buffer
* @throws IllegalArgumentException if buffer or predicate is null
* @throws IllegalArgumentException if the buffer contains invalid elements
*/
public static Buffer decorate(Buffer buffer, Predicate predicate) {
return new PredicatedBuffer(buffer, predicate);
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
* <p>
* If there are any elements already in the collection being decorated, they
* are validated.
*
* @param buffer the buffer to decorate, must not be null
* @param predicate the predicate to use for validation, must not be null
* @throws IllegalArgumentException if buffer or predicate is null
* @throws IllegalArgumentException if the buffer contains invalid elements
*/
protected PredicatedBuffer(Buffer buffer, Predicate predicate) {
super(buffer, predicate);
}
/**
* Gets the buffer being decorated.
*
* @return the decorated buffer
*/
protected Buffer getBuffer() {
return (Buffer) getCollection();
}
//-----------------------------------------------------------------------
public Object get() {
return getBuffer().get();
}
public Object remove() {
return getBuffer().remove();
}
}