/*
 * $Id$
 *
 * Copyright (c) 2004, 2009, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package com.sun.javatest.util;

import java.util.Enumeration;
import java.util.Iterator;
import java.util.Properties;
import java.util.Set;
import java.util.TreeSet;

/**
 * A subtype of Properties for which the keys method will return a sorted enumeration.
 * This means that the store method will write the various properties in sorted order.
 */
public class SortedProperties extends Properties
{
    // override Keys() to return a sorted set
    public Enumeration<Object> keys() {
        Set<Object> s = new TreeSet<>(); // ordered
        for (Enumeration<?> e = super.keys(); e.hasMoreElements(); ) {
            s.add(e.nextElement());
        }

        final Iterator<?> iter = s.iterator();
        return new Enumeration<Object>() {
                public boolean hasMoreElements() {
                    return iter.hasNext();
                }
                public Object nextElement() {
                    return iter.next();
                }
            };
    }
}