OrderedProperties.java

/*
 * Copyright 2011 Matthias van der Vlies
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package core;

import java.util.Collections;
import java.util.Enumeration;
import java.util.LinkedHashSet;
import java.util.Properties;
import java.util.Set;

/**
 * Special Properties class able to maintain line order for properties file
 */
public class OrderedProperties extends Properties {

    private final LinkedHashSet<Object> keys = new LinkedHashSet<Object>();

    @Override
    public Enumeration<Object> keys() {
        return Collections.<Object>enumeration(keys);
    }

    @Override
    public Set<Object> keySet() {
    	return keys;
    }
    
    @Override
    public Object put(Object key, Object value) {
        keys.add(key);
        return super.put(key, value);
    }
}