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Java > Open Source Codes > org > apache > activemq > transport > CommandJoiner


1 /**
2  *
3  * Licensed to the Apache Software Foundation (ASF) under one or more
4  * contributor license agreements. See the NOTICE file distributed with
5  * this work for additional information regarding copyright ownership.
6  * The ASF licenses this file to You under the Apache License, Version 2.0
7  * (the "License"); you may not use this file except in compliance with
8  * the License. You may obtain a copy of the License at
9  *
10  * http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18 package org.apache.activemq.transport;
19
20 import java.io.ByteArrayOutputStream JavaDoc;
21 import java.io.DataInputStream JavaDoc;
22 import java.io.IOException JavaDoc;
23
24 import org.apache.activemq.command.Command;
25 import org.apache.activemq.command.LastPartialCommand;
26 import org.apache.activemq.command.PartialCommand;
27 import org.apache.activemq.openwire.OpenWireFormat;
28 import org.apache.activemq.util.ByteArrayInputStream;
29 import org.apache.commons.logging.Log;
30 import org.apache.commons.logging.LogFactory;
31
32 /**
33  * Joins together of partial commands which were split into individual chunks of
34  * data.
35  *
36  * @version $Revision: 464110 $
37  */
38 public class CommandJoiner extends TransportFilter {
39     private static final Log log = LogFactory.getLog(CommandJoiner.class);
40
41     private ByteArrayOutputStream JavaDoc out = new ByteArrayOutputStream JavaDoc();
42     private OpenWireFormat wireFormat;
43
44     public CommandJoiner(Transport next, OpenWireFormat wireFormat) {
45         super(next);
46         this.wireFormat = wireFormat;
47     }
48
49     public void onCommand(Object JavaDoc o) {
50         Command command = (Command) o;
51         byte type = command.getDataStructureType();
52         if (type == PartialCommand.DATA_STRUCTURE_TYPE || type == LastPartialCommand.DATA_STRUCTURE_TYPE) {
53             PartialCommand header = (PartialCommand) command;
54             byte[] partialData = header.getData();
55             try {
56                 out.write(partialData);
57             }
58             catch (IOException JavaDoc e) {
59                 getTransportListener().onException(e);
60             }
61             if (type == LastPartialCommand.DATA_STRUCTURE_TYPE) {
62                 try {
63                     byte[] fullData = out.toByteArray();
64                     out.reset();
65                     DataInputStream JavaDoc dataIn = new DataInputStream JavaDoc(new ByteArrayInputStream(fullData));
66                     Command completeCommand = (Command) wireFormat.unmarshal(dataIn);
67
68                     LastPartialCommand lastCommand = (LastPartialCommand) command;
69                     lastCommand.configure(completeCommand);
70
71                     getTransportListener().onCommand(completeCommand);
72                 }
73                 catch (IOException JavaDoc e) {
74                     log.warn("Failed to unmarshal partial command: " + command);
75                     getTransportListener().onException(e);
76                 }
77             }
78         }
79         else {
80             getTransportListener().onCommand(command);
81         }
82     }
83
84     public void stop() throws Exception JavaDoc {
85         super.stop();
86         out = null;
87     }
88
89     public String JavaDoc toString() {
90         return next.toString();
91     }
92 }
93
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