PacketTransactionTask xref

View Javadoc

    1   /***
    2    *
    3    * Copyright 2004 Protique Ltd
    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   **/
    18  package org.codehaus.activemq.service.impl;
    19
    20  import org.codehaus.activemq.broker.BrokerClient;
    21  import org.codehaus.activemq.broker.impl.BrokerClientImpl;
    22  import org.codehaus.activemq.message.ActiveMQMessage;
    23  import org.codehaus.activemq.message.DefaultWireFormat;
    24  import org.codehaus.activemq.message.MessageAck;
    25  import org.codehaus.activemq.message.Packet;
    26  import org.codehaus.activemq.message.WireFormat;
    27  import org.codehaus.activemq.service.TransactionTask;
    28  import org.codehaus.activemq.util.JMSExceptionHelper;
    29
    30  import javax.jms.JMSException;
    31  import java.io.Externalizable;
    32  import java.io.IOException;
    33  import java.io.ObjectInput;
    34  import java.io.ObjectOutput;
    35
    36  /***
    37   * @version $Revision: 1.2 $
    38   */
    39  public abstract class PacketTransactionTask implements TransactionTask, Externalizable {
    40      private static final long serialVersionUID = -5754338187296859149L;
    41      private static transient final WireFormat wireFormat = new DefaultWireFormat();
    42
    43      private BrokerClient brokerClient;
    44      private Packet packet;
    45
    46
    47      public static TransactionTask fromBytes(byte[] data) throws IOException {
    48          Packet packet = wireFormat.fromBytes(data);
    49          return createTask(packet);
    50      }
    51
    52      public byte[] toBytes() throws JMSException, IOException {
    53          return wireFormat.toBytes(packet);
    54      }
    55
    56      public static TransactionTask readTask(ObjectInput in) throws IOException {
    57          Packet packet = readPacket(in);
    58          return createTask(packet);
    59      }
    60
    61      public static TransactionTask createTask(Packet packet) throws IOException {
    62          if (packet instanceof MessageAck) {
    63              return new MessageAckTransactionTask(null, (MessageAck) packet);
    64          }
    65          else if (packet instanceof ActiveMQMessage) {
    66              return new SendMessageTransactionTask(null, (ActiveMQMessage) packet);
    67          }
    68          else {
    69              throw new IOException("Unexpected packet type: " + packet);
    70          }
    71      }
    72
    73      public static void writeTask(TransactionTask task, ObjectOutput out) throws IOException {
    74          if (task instanceof PacketTransactionTask) {
    75              PacketTransactionTask packetTask = (PacketTransactionTask) task;
    76              writePacket(packetTask.getPacket(), out);
    77          }
    78          else {
    79              out.writeObject(task);
    80          }
    81      }
    82
    83      protected PacketTransactionTask(BrokerClient brokerClient, Packet packet) {
    84          this.brokerClient = brokerClient;
    85          this.packet = packet;
    86      }
    87
    88      public Packet getPacket() {
    89          return packet;
    90      }
    91
    92      public void writeExternal(ObjectOutput out) throws IOException {
    93          writePacket(packet, out);
    94      }
    95
    96      public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
    97          packet = readPacket(in);
    98      }
    99
    100
    101     // Implementation methods
    102     //-------------------------------------------------------------------------
    103     protected BrokerClient createBrokerClient(String consumerId) throws JMSException {
    104         BrokerClientImpl answer = new BrokerClientImpl();
    105         return answer;
    106     }
    107
    108     protected BrokerClient getBrokerClient(String consumerId) throws JMSException {
    109         // TODO replace when tested recovery
    110         brokerClient = createBrokerClient(consumerId);
    111         /*
    112         if (brokerClient == null) {
    113         brokerClient = createBrokerClient(consumerId);
    114         }
    115         */
    116         return brokerClient;
    117     }
    118
    119     protected static void writePacket(Packet packet, ObjectOutput out) throws IOException {
    120         try {
    121             wireFormat.writePacket(packet, out);
    122         }
    123         catch (JMSException e) {
    124             throw JMSExceptionHelper.newIOException(e);
    125         }
    126     }
    127
    128     protected static Packet readPacket(ObjectInput in) throws IOException {
    129         return wireFormat.readPacket(in);
    130     }
    131 }