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 *     https://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.reloading;
018
019import org.apache.commons.configuration2.event.Event;
020import org.apache.commons.configuration2.event.EventType;
021
022/**
023 * <p>
024 * An event that is fired when a reload operation is required.
025 * </p>
026 * <p>
027 * Events of this type are generated by {@link ReloadingController} if the need for a reload operation is detected. From
028 * the pay-load of the event information about the components involved is available.
029 * </p>
030 *
031 * @since 2.0
032 */
033public class ReloadingEvent extends Event {
034
035    /** The common event super type for all reloading events. */
036    public static final EventType<ReloadingEvent> ANY = new EventType<>(Event.ANY, "RELOAD");
037
038    /**
039     * The serial version UID.
040     */
041    private static final long serialVersionUID = 20140701L;
042
043    /** Stores additional data about this event. */
044    private final Object data;
045
046    /**
047     * Creates a new instance of {@code ReloadingEvent} and initializes it.
048     *
049     * @param source the controller which generated this event
050     * @param addData an arbitrary data object to be evaluated by event listeners
051     */
052    public ReloadingEvent(final ReloadingController source, final Object addData) {
053        super(source, ANY);
054        data = addData;
055    }
056
057    /**
058     * Gets the {@code ReloadingController} which caused this event.
059     *
060     * @return the responsible {@code ReloadingController}
061     */
062    public ReloadingController getController() {
063        return (ReloadingController) getSource();
064    }
065
066    /**
067     * Gets an object with additional data about the reload operation. This is the object that was passed to the
068     * {@link ReloadingController} when it was asked to do a reloading check. This is a generic mechanism to pass arbitrary
069     * data to reloading listeners.
070     *
071     * @return additional data about the reload operation (can be <strong>null</strong>)
072     */
073    public Object getData() {
074        return data;
075    }
076}