OrderedProperties.java

/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

package com.liferay.portal.kernel.util;

import java.util.Enumeration;
import java.util.Properties;
import java.util.Vector;

/**
 * @author Brian Wing Shun Chan
 */
public class OrderedProperties extends Properties {

	public OrderedProperties() {
		_names = new Vector<>();
	}

	@Override
	public Enumeration<String> propertyNames() {
		return _names.elements();
	}

	@Override
	public Object put(Object key, Object value) {
		if (_names.contains(key)) {
			_names.remove(key);
		}

		_names.add((String)key);

		return super.put(key, value);
	}

	@Override
	public Object remove(Object key) {
		_names.remove(key);

		return super.remove(key);
	}

	private final Vector<String> _names;

}