/* * 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; import java.util.Collection; /** * Defines a collection that allows objects to be removed in some well-defined order. * <p> * The removal order can be based on insertion order (eg, a FIFO queue or a * LIFO stack), on access order (eg, an LRU cache), on some arbitrary comparator * (eg, a priority queue) or on any other well-defined ordering. * <p> * Note that the removal order is not necessarily the same as the iteration * order. A <code>Buffer</code> implementation may have equivalent removal * and iteration orders, but this is not required. * <p> * This interface does not specify any behavior for * {@link Object#equals(Object)} and {@link Object#hashCode} methods. It * is therefore possible for a <code>Buffer</code> implementation to also * also implement {@link java.util.List}, {@link java.util.Set} or * {@link Bag}. * <p> * <strong>Note:</strong> this class should be bytecode-identical to the * version in commons collections. This is required to allow backwards * compability with both previous versions of BeanUtils and also allow * coexistance with both collections 2.1 and 3.0. * * @since Commons Collections 2.1 * @version $Revision: 555824 $ $Date: 2007-07-13 01:27:15 +0100 (Fri, 13 Jul 2007) $ * * @author Avalon * @author Berin Loritsch * @author Paul Jack * @author Stephen Colebourne */ public interface Buffer extends Collection { /** * Gets and removes the next object from the buffer. * * @return the next object in the buffer, which is also removed * @throws BufferUnderflowException if the buffer is already empty */ Object remove(); /** * Gets the next object from the buffer without removing it. * * @return the next object in the buffer, which is not removed * @throws BufferUnderflowException if the buffer is empty */ Object get(); }