    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;
    018
    019/**
    020 * <p>
    021 * Definition of an interface to be implemented by {@code Configuration}
    022 * implementations which support a special initialization method.
    023 * </p>
    024 * <p>
    025 * This interface is mainly evaluated by <em>configuration builder</em>
    026 * implementations: If a newly created configuration instance implements this
    027 * interface, the builder calls the {@code initialize()} method. This gives
    028 * {@code Configuration} classes the opportunity to perform additional
    029 * initializations after all properties passed to the builder have been set.
    030 * </p>
    031 * <p>
    032 * Another use case for this interface is to perform initializations directly
    033 * which otherwise would have been done lazily. Lazy initializations can be
    034 * problematic regarding thread-safety. If in contrast a configuration instance
    035 * has been fully initialized when it is returned from the builder, it may be
    036 * used with a {@code NoOpSynchronizer} if it is not modified.
    037 * </p>
    038 *
    039 * @since 2.0
    040 */
    041public interface Initializable
    042{
    043    /**
    044     * Initializes this object. A concrete implementation can use this method to
    045     * perform arbitrary initialization. Typically, this method is invoked by a
    046     * <em>configuration builder</em>. In this case, the builder's lock is held,
    047     * so that all member fields set by this method are safely published.
    048     */
    049    void initialize();
    050}