ConfigQuery.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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
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 * KIND, either express or implied.  See the License for the
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 */
package org.apache.tamaya;

/**
 * Models a function that maps a given {@link Configuration} to something else. This can be used
 * to model additional functionality and applying it to a given {@link Configuration} instance by
 * calling the {@link Configuration#query(ConfigQuery)} method.
 */
public interface ConfigQuery<T> {

    /**
     * Creates a result based on the given Configuration. Queries basically acts similar to
     * operators, whereas they returns any kind of result.
     *
     * @param config the input configuration, not {@code null}.
     * @return the query result.
     */
    T query(Configuration config);
}