dxarraydeque.java

用Java写的面相对象的数据库管理系统

// You can redistribute this software and/or modify it under the terms of
// the Ozone Library License version 1 published by ozone-db.org.
//
// The original code and portions created by SMB are
// Copyright (C) 1997-2000 by SMB GmbH. All rights reserved.
//
// $Id: DxArrayDeque.java,v 1.9 2000/10/28 16:55:14 daniela Exp $

package org.ozoneDB.DxLib;


/**
 * @author <a href="http://www.softwarebuero.de/">SMB</a>
 * @version $Revision: 1.9 $Date: 2000/10/28 16:55:14 $
 */
public class DxArrayDeque extends DxArrayBag implements DxDeque {
    
    final static long serialVersionUID = 1L;
    
    
    public DxArrayDeque() {
    }
    
    
    public DxArrayDeque( int initSpace ) {
        super( initSpace );
    }
    
    
    public Object peek() {
        return peekBottom();
    } 
    
    
    public Object peekTop() {
        return isEmpty() ? null : elementAtIndex( size() - 1 );
    } 
    
    
    public Object peekBottom() {
        return isEmpty() ? null : elementAtIndex( 0 );
    } 
    
    
    public synchronized void push( Object obj ) {
        pushTop( obj );
    } 
    
    
    public synchronized void pushTop( Object obj ) {
        insertAtIndex( obj, size() );
    } 
    
    
    public synchronized void pushBottom( Object obj ) {
        insertAtIndex( obj, 0 );
    } 
    
    
    public Object pop() {
        return popTop();
    } 
    
    
    public Object popTop() {
        return isEmpty() ? null : deleteAtIndex( size() - 1 );
    } 
    
    
    public Object popBottom() {
        return isEmpty() ? null : deleteAtIndex( 0 );
    } 
    
}