orderedmap.java

Rapla是一个灵活的多用户资源管理系统。它提供的一些功能有：日历GUI

/*--------------------------------------------------------------------------*
 | Copyright (C) 2006 Christopher Kohlhaas                                  |
 |                                                                          |
 | This program is free software; you can redistribute it and/or modify     |
 | it under the terms of the GNU General Public License as published by the |
 | Free Software Foundation. A copy of the license has been included with   |
 | these distribution in the COPYING file, if not go to www.fsf.org         |
 |                                                                          |
 | As a special exception, you are granted the permissions to link this     |
 | program with every library, which license fulfills the Open Source       |
 | Definition as published by the Open Source Initiative (OSI).             |
 *--------------------------------------------------------------------------*/
package org.rapla.components.util;

import java.util.*;
/**    <p>An implemention of a map that keeps the values (not the keys) sorted.</p> */
public class OrderedMap extends HashMap  {
    private static final long serialVersionUID = 1L;

    SortedSet sorted;

    public OrderedMap() {
        super();
        sorted = new TreeSet();
    }

    public OrderedMap(Comparator comparator) {
        super();
        sorted = new TreeSet(comparator);
    }

    public Object put(Object key,Object value) {
	Object result = super.put(key,value);
	if (result != null) {
	    //#TODO This is not very performant
	    rebuildTree();
	    //sorted.add(value);
	} else {
	    sorted.add(value);
	}
	return result;
    }

    private void rebuildTree() {
	sorted.clear();
	sorted.addAll(super.values());
    }

    public void putAll(Map all) {
	super.putAll(all);
	rebuildTree();
    }

    public Object remove(Object key) {
	Object result = super.remove(key);
        if (result != null) 
            if (!sorted.remove(result))
		rebuildTree();
        return result;
    }

    public void clear() {
        super.clear();
        sorted.clear();
    }
      
    public Collection values() {
        return sorted;
    }
}