/*
* Copyright (c) 2002-2003 by OpenSymphony
* All rights reserved.
*/
package com.opensymphony.util;
/* ====================================================================
* The OpenSymphony Software License, Version 1.1
*
* (this license is derived and fully compatible with the Apache Software
* License - see http://www.apache.org/LICENSE.txt)
*
* Copyright (c) 2001 The OpenSymphony Group. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* OpenSymphony Group (http://www.opensymphony.com/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "OpenSymphony" and "The OpenSymphony Group"
* must not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact [email protected] .
*
* 5. Products derived from this software may not be called "OpenSymphony"
* or "OSCore", nor may "OpenSymphony" or "OSCore" appear in their
* name, without prior written permission of the OpenSymphony Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*/
import java.util.*;
/**
* Extention of <code>java.util.HashMap</code> that can retain original order
* elements were add in.
*
* <p>Uses an internal <code>java.util.LinkedList</code> which can be iterated
* through by accessing {@link #iterator()}.</p>
*
* @author <a href="mailto:[email protected]">Joe Walnes</a>
* @version $Revision: 11 $
* @deprecated If you need special data structures like this, we recommend you
* check out the Jakarta commons-collections project.
* @see java.util.HashMap
*/
public class OrderedMap extends HashMap {
//~ Instance fields ////////////////////////////////////////////////////////
private List keyOrder = new LinkedList();
//~ Methods ////////////////////////////////////////////////////////////////
/**
* Overrides superclass.
*/
public void clear() {
keyOrder.clear();
}
/**
* Return keys in original order.
*
* @return Iteration of keys.
*/
public Iterator iterator() {
return keyOrder.iterator();
}
/**
* Overrides superclass.
*/
public Object put(Object key, Object value) {
keyOrder.add(key);
return super.put(key, value);
}
/**
* Overrides superclass.
*/
public Object remove(Object key) {
keyOrder.remove(key);
return super.remove(key);
}
}
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