| /* |
| * Copyright 2001-2004 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; |
| |
| /** |
| * Defines a collection for priority queues, which can insert, peek and pop. |
| * <p> |
| * This interface is now replaced by the <code>Buffer</code> interface. |
| * |
| * @deprecated Replaced by the Buffer interface and implementations in buffer subpackage. |
| * Due to be removed in v4.0. |
| * @since Commons Collections 1.0 |
| * @version $Revision: 1.1 $ $Date: 2009/05/27 22:16:18 $ |
| * |
| * @author Peter Donald |
| */ |
| public interface PriorityQueue { |
| |
| /** |
| * Clear all elements from queue. |
| */ |
| void clear(); |
| |
| /** |
| * Test if queue is empty. |
| * |
| * @return true if queue is empty else false. |
| */ |
| boolean isEmpty(); |
| |
| /** |
| * Insert an element into queue. |
| * |
| * @param element the element to be inserted |
| * |
| * @throws ClassCastException if the specified <code>element</code>'s |
| * type prevents it from being compared to other items in the queue to |
| * determine its relative priority. |
| */ |
| void insert(Object element); |
| |
| /** |
| * Return element on top of heap but don't remove it. |
| * |
| * @return the element at top of heap |
| * @throws java.util.NoSuchElementException if <code>isEmpty() == true</code> |
| */ |
| Object peek(); |
| |
| /** |
| * Return element on top of heap and remove it. |
| * |
| * @return the element at top of heap |
| * @throws java.util.NoSuchElementException if <code>isEmpty() == true</code> |
| */ |
| Object pop(); |
| |
| } |