    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 */
    017
    018package org.apache.commons.net.io;
    019
    020import java.util.EventListener;
    021
    022import org.apache.commons.net.util.ListenerList;
    023
    024/**
    025 * The CopyStreamAdapter will relay CopyStreamEvents to a list of listeners
    026 * when either of its bytesTransferred() methods are called.  Its purpose
    027 * is to facilitate the notification of the progress of a copy operation
    028 * performed by one of the static copyStream() methods in
    029 * org.apache.commons.io.Util to multiple listeners.  The static
    030 * copyStream() methods invoke the
    031 * bytesTransfered(long, int) of a CopyStreamListener for performance
    032 * reasons and also because multiple listeners cannot be registered given
    033 * that the methods are static.
    034 * <p>
    035 * <p>
    036 * @see CopyStreamEvent
    037 * @see CopyStreamListener
    038 * @see Util
    039 * @version $Id: CopyStreamAdapter.java 1489361 2013-06-04 09:48:36Z sebb $
    040 */
    041public class CopyStreamAdapter implements CopyStreamListener
    042{
    043    private final ListenerList internalListeners;
    044
    045    /**
    046     * Creates a new copyStreamAdapter.
    047     */
    048    public CopyStreamAdapter()
    049    {
    050        internalListeners = new ListenerList();
    051    }
    052
    053    /**
    054     * This method is invoked by a CopyStreamEvent source after copying
    055     * a block of bytes from a stream.  The CopyStreamEvent will contain
    056     * the total number of bytes transferred so far and the number of bytes
    057     * transferred in the last write.  The CopyStreamAdapater will relay
    058     * the event to all of its registered listeners, listing itself as the
    059     * source of the event.
    060     * @param event The CopyStreamEvent fired by the copying of a block of
    061     *              bytes.
    062     */
    063//    @Override
    064    public void bytesTransferred(CopyStreamEvent event)
    065    {
    066        for (EventListener listener : internalListeners)
    067        {
    068            ((CopyStreamListener) (listener)).bytesTransferred(event);
    069        }
    070    }
    071
    072    /**
    073     * This method is not part of the JavaBeans model and is used by the
    074     * static methods in the org.apache.commons.io.Util class for efficiency.
    075     * It is invoked after a block of bytes to inform the listener of the
    076     * transfer.  The CopyStreamAdapater will create a CopyStreamEvent
    077     * from the arguments and relay the event to all of its registered
    078     * listeners, listing itself as the source of the event.
    079     * @param totalBytesTransferred  The total number of bytes transferred
    080     *         so far by the copy operation.
    081     * @param bytesTransferred  The number of bytes copied by the most recent
    082     *          write.
    083     * @param streamSize The number of bytes in the stream being copied.
    084     *        This may be equal to CopyStreamEvent.UNKNOWN_STREAM_SIZE if
    085     *        the size is unknown.
    086     */
    087//    @Override
    088    public void bytesTransferred(long totalBytesTransferred,
    089                                 int bytesTransferred, long streamSize)
    090    {
    091        for (EventListener listener : internalListeners)
    092        {
    093            ((CopyStreamListener) (listener)).bytesTransferred(
    094                    totalBytesTransferred, bytesTransferred, streamSize);
    095        }
    096    }
    097
    098    /**
    099     * Registers a CopyStreamListener to receive CopyStreamEvents.
    100     * Although this method is not declared to be synchronized, it is
    101     * implemented in a thread safe manner.
    102     * @param listener  The CopyStreamlistener to register.
    103     */
    104    public void addCopyStreamListener(CopyStreamListener listener)
    105    {
    106        internalListeners.addListener(listener);
    107    }
    108
    109    /**
    110     * Unregisters a CopyStreamListener.  Although this method is not
    111     * synchronized, it is implemented in a thread safe manner.
    112     * @param listener  The CopyStreamlistener to unregister.
    113     */
    114    public void removeCopyStreamListener(CopyStreamListener listener)
    115    {
    116        internalListeners.removeListener(listener);
    117    }
    118}