OrderedProperties.java

package de.r3s6.maven.constcreator;
/*
 * Copyright 2021 Ralf Schandl
 *
 * 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.
 */

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

/**
 * Thin wrapper around {@link Properties} to keep insert order.
 * <p>
 * Only used for reading properties.
 * <p>
 * <b>WARNING</b>: This is just enough for the usage in this maven plugin.
 *
 * @author Ralf Schandl
 */
@SuppressWarnings("java:S2160")
public class OrderedProperties extends Properties {

    private static final long serialVersionUID = 1L;

    /** Keyset preserving insert order. */
    private final HashSet<Object> keySet = new LinkedHashSet<>();

    @Override
    public synchronized Object put(final Object key, final Object value) {
        keySet.add(key);
        return super.put(key, value);
    }

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

    @Override
    public Set<Object> keySet() {
        return Collections.unmodifiableSet(keySet);
    }

    @Override
    public Set<java.util.Map.Entry<Object, Object>> entrySet() {
        throw new UnsupportedOperationException("entrySet() not implemented. Use keySet()");
    }

    // Will never be used in our scenario
    @Override
    public synchronized void clear() {
        keySet.clear();
        super.clear();
    }

    // Will never be used in our scenario
    @Override
    public synchronized Object remove(final Object key) {
        keySet.remove(key);
        return super.remove(key);
    }

    // Will never be used in our scenario
    @Override
    public synchronized boolean remove(final Object key, final Object value) {
        if (super.remove(key, value)) {
            keySet.remove(key);
            return true;
        } else {
            return false;
        }
    }
}