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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.transport;
19  
20  import org.apache.commons.logging.Log;
21  import org.apache.commons.logging.LogFactory;
22  import org.codehaus.activemq.ConfigurationException;
23  import org.codehaus.activemq.message.WireFormat;
24  import org.codehaus.activemq.transport.reliable.ReliableTransportChannel;
25  import org.codehaus.activemq.util.Callback;
26  import org.codehaus.activemq.util.ExceptionTemplate;
27  import org.codehaus.activemq.util.MapHelper;
28  
29  import javax.jms.JMSException;
30  import java.net.URI;
31  import java.net.URISyntaxException;
32  import java.util.List;
33  import java.util.Map;
34  
35  /***
36   * A {@link ReliableTransportChannel} which uses a {@link DiscoveryAgent} to discover remote broker
37   * instances and dynamically connect to them.
38   *
39   * @version $Revision: 1.3 $
40   */
41  public class DiscoveryTransportChannel extends ReliableTransportChannel implements DiscoveryListener {
42      private static final Log log = LogFactory.getLog(DiscoveryTransportChannel.class);
43  
44  
45      private DiscoveryAgent discoveryAgent;
46      private String remoteUserName;
47      private String remotePassword;
48  
49  
50      public DiscoveryTransportChannel(WireFormat wireFormat, DiscoveryAgent discoveryAgent) {
51          super(wireFormat);
52          this.discoveryAgent = discoveryAgent;
53      }
54  
55      public void start() throws JMSException {
56          if (discoveryAgent == null) {
57              throw new ConfigurationException("Must be configured with a discoveryAgent property");
58          }
59  
60          // lets pass into the agent the broker name and connection details
61          discoveryAgent.setDiscoveryListener(this);
62          discoveryAgent.start();
63  
64          super.start();
65      }
66  
67      public void stop() {
68          ExceptionTemplate template = new ExceptionTemplate();
69          template.run(new Callback() {
70              public void execute() throws Throwable {
71                  discoveryAgent.stop();
72              }
73          });
74          template.run(new Callback() {
75              public void execute() throws Throwable {
76                  DiscoveryTransportChannel.super.stop();
77              }
78          });
79          Throwable e = template.getFirstException();
80          log.warn("Failed to stop the transport channel cleanly due to: " + e, e);
81      }
82  
83  
84      public synchronized void addService(DiscoveryEvent event) {
85          Map details = event.getServiceDetails();
86          String url = MapHelper.getString(details, "connectURL");
87          if (url != null) {
88              try {
89                  URI uri = new URI(url);
90                  List urlList = getUris();
91                  if (!urlList.contains(uri)) {
92                      log.info("Adding new broker connection URL: " + uri + " with details: " + details);
93  
94                      urlList.add(uri);
95                  }
96              }
97              catch (URISyntaxException e) {
98                  log.warn("Could not connect to remote URI: " + url + " due to bad URI syntax: " + e, e);
99              }
100         }
101     }
102 
103     public synchronized void removeService(DiscoveryEvent event) {
104         Map details = event.getServiceDetails();
105         String url = MapHelper.getString(details, "connectURL");
106         if (url != null) {
107             try {
108                 URI uri = new URI(url);
109                 synchronized (this) {
110                     List urlList = getUris();
111                     if (urlList.remove(uri)) {
112                         log.info("Removing broker connection URL: " + uri);
113                     }
114                 }
115             }
116             catch (URISyntaxException e) {
117                 log.warn("Could not remove remote URI: " + url + " due to bad URI syntax: " + e, e);
118             }
119         }
120     }
121 
122     // Properties
123     //-------------------------------------------------------------------------
124     public DiscoveryAgent getDiscoveryAgent() {
125         return discoveryAgent;
126     }
127 
128     public void setDiscoveryAgent(DiscoveryAgent discoveryAgent) {
129         this.discoveryAgent = discoveryAgent;
130     }
131 
132 
133     public String getRemotePassword() {
134         return remotePassword;
135     }
136 
137     public void setRemotePassword(String remotePassword) {
138         this.remotePassword = remotePassword;
139     }
140 
141     public String getRemoteUserName() {
142         return remoteUserName;
143     }
144 
145     public void setRemoteUserName(String remoteUserName) {
146         this.remoteUserName = remoteUserName;
147     }
148 
149 }