特殊权限(t)之粘着位

/*
* $Id: OrderedMap.java,v 1.1 2009/04/28 06:38:23 E000315 Exp $
*
*  Copyright (c) 2001, 2002 The Open For Business Project - www.ofbiz.org
*
*  Permission is hereby granted, free of charge, to any person obtaining a
*  copy of this software and associated documentation files (the "Software"),
*  to deal in the Software without restriction, including without limitation
*  the rights to use, copy, modify, merge, publish, distribute, sublicense,
*  and/or sell copies of the Software, and to permit persons to whom the
*  Software is furnished to do so, subject to the following conditions:
*
*  The above copyright notice and this permission notice shall be included
*  in all copies or substantial portions of the Software.
*
*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
*  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
*  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
*  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
*  CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT
*  OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
*  THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.peter.apps.util;

import java.util.*;

/**
* OrderedMap - HashMap backed by a linked list.
*
* @author     <a href="mailto:jaz@jflow.net">Andy Zeneski</a>
* @version    $Revision: 1.1 $
* @since      2.0
*/
public class OrderedMap extends HashMap {

private List orderedKeys = new LinkedList();

/**
* @see java.util.Map#keySet()
*/
public Set keySet() {
return new OrderedSet(orderedKeys);
}

/**
* @see java.util.Map#put(java.lang.Object, java.lang.Object)
*/
public Object put(Object key, Object value) {
if (!orderedKeys.contains(key))
orderedKeys.add(key);
return super.put(key, value);
}

/**
* @see java.util.Map#clear()
*/
public void clear() {
super.clear();
orderedKeys.clear();
}

/**
* @see java.util.Map#remove(java.lang.Object)
*/
public Object remove(Object key) {
if (orderedKeys.contains(key))
orderedKeys.remove(key);
return super.remove(key);
}
}