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
019import java.util.Map;
020
021/**
022 * <p>
023 * An interface to be implemented by objects which can be used to parameterize a {@link ConfigurationBuilder}.
024 * </p>
025 * <p>
026 * This interface is part of a Java DSL for creating and initializing builders for specific {@code Configuration}
027 * classes. Concrete implementations typically collect a set of related properties for the builder. There will be
028 * specific set methods for providing values for these properties. Then, this interface requires a generic
029 * {@code getParameters()} method which has to return all property values as a map. When constructing the builder the
030 * map is evaluated to define properties of the {@code Configuration} objects to be constructed.
031 * </p>
032 *
033 * @since 2.0
034 */
035public interface BuilderParameters {
036    /**
037     * Constant for a prefix for reserved initialization parameter keys. If a parameter was set whose key starts with this
038     * prefix, it is filtered out before the initialization of a newly created result object. This mechanism allows
039     * implementing classes to store specific configuration data in the parameters map which does not represent a property
040     * value for the result object.
041     */
042    String RESERVED_PARAMETER_PREFIX = "config-";
043
044    /**
045     * Gets a map with all parameters defined by this objects. The keys of the map correspond to concrete properties
046     * supported by the {@code Configuration} implementation class the builder produces. The values are the corresponding
047     * property values. The return value must not be <b>null</b>.
048     *
049     * @return a map with builder parameters
050     */
051    Map<String, Object> getParameters();
052}