View Javadoc

    1   /***
    2    *
    3    * Copyright 2004 Hiram Chirino
    4    *
    5    *  Licensed under the Apache License, Version 2.0 (the "License");
    6    *  you may not use this file except in compliance with the License.
    7    *  You may obtain a copy of the License at
    8    *
    9    *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   *  Unless required by applicable law or agreed to in writing, software
    12   *  distributed under the License is distributed on an "AS IS" BASIS,
    13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   *  See the License for the specific language governing permissions and
    15   *  limitations under the License.
    16   */
    17  package org.activeio.filter;
    18
    19  import java.io.IOException;
    20
    21  import org.activeio.AsynchChannel;
    22  import org.activeio.FilterAsynchChannel;
    23  import org.activeio.Packet;
    24
    25  /***
    26   * This PacketAggregatingAsynchChannel can be used when the client is sending a
    27   * 'record' style packet down the channel stack and needs receiving end to
    28   * receive the same 'record' packets.
    29   *
    30   * This is very usefull since in general, a channel does not garantee that a
    31   * Packet that is sent down will not be fragmented or combined with other Packet
    32   * objects.
    33   *
    34   * This {@see org.activeio.AsynchChannel} adds a 4 byte header
    35   * to each packet that is sent down.
    36   *
    37   * @version $Revision$
    38   */
    39  final public class PacketAggregatingAsynchChannel extends FilterAsynchChannel {
    40
    41      private final PacketAggregator aggregator = new PacketAggregator() {
    42          protected void packetAssembled(Packet packet) {
    43              getAsynchChannelListener().onPacket(packet);
    44          }
    45      };
    46
    47      public PacketAggregatingAsynchChannel(AsynchChannel next) {
    48          super(next);
    49      }
    50
    51      public void onPacket(Packet packet) {
    52          try {
    53              aggregator.addRawPacket(packet);
    54          } catch (IOException e) {
    55              getAsynchChannelListener().onPacketError(e);
    56          }
    57      }
    58
    59      public void write(Packet packet) throws IOException {
    60          getNext().write(aggregator.getHeader(packet));
    61          getNext().write(packet);
    62      }
    63
    64  }