001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.configuration2.builder;
018
019/**
020 * <p>
021 * Definition of an interface for setting default values for specific
022 * configuration parameter objects.
023 * </p>
024 * <p>
025 * An object implementing this interface knows how to initialize a parameters
026 * object of a specific class with default values. Such objects can be
027 * registered at the {@link org.apache.commons.configuration2.builder.fluent.Parameters
028 * Parameters} class. Whenever a specific parameters
029 * object is created all registered {@code DefaultParametersHandler} objects
030 * that can handle this parameters type are invoked, so that they get the chance
031 * to perform arbitrary initialization.
032 * </p>
033 *
034 * @since 2.0
035 * @param <T> the type of parameters supported by this handler
036 */
037public interface DefaultParametersHandler<T>
038{
039    /**
040     * Initializes the specified parameters object with default values. This
041     * method is called after the parameters object was created and before it is
042     * passed to the calling code. A concrete implementation can perform
043     * arbitrary initializations. Note that if there are multiple
044     * {@code DefaultParametersHandler} objects registered supporting this
045     * parameters type they are called in the order they have been registered.
046     * So handlers registered later can override initializations done by
047     * handlers registered earlier.
048     *
049     * @param parameters the parameters object to be initialized
050     */
051    void initializeDefaults(T parameters);
052}