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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements. See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache license, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License. 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.apache.logging.log4j.core.net;
18  
19  import org.apache.logging.log4j.LogManager;
20  import org.apache.logging.log4j.Logger;
21  import org.apache.logging.log4j.core.AbstractServer;
22  import org.apache.logging.log4j.core.LogEvent;
23  
24  import javax.jms.JMSException;
25  import javax.jms.ObjectMessage;
26  import javax.naming.Context;
27  import javax.naming.NameNotFoundException;
28  import javax.naming.NamingException;
29  
30  /**
31   * Abstract base class for receiving LogEvents over JMS. This class expects all messages to be serialized log events.
32   */
33  public abstract class AbstractJMSReceiver extends AbstractServer implements javax.jms.MessageListener {
34  
35      /**
36       * Logger to capture diagnostics.
37       */
38      protected Logger logger = LogManager.getLogger(this.getClass().getName());
39  
40      /**
41       * Listener that receives the event.
42       * @param message The received message.
43       */
44      public void onMessage(final javax.jms.Message message) {
45  
46          try {
47              if (message instanceof ObjectMessage) {
48                  final ObjectMessage objectMessage = (ObjectMessage) message;
49                  log((LogEvent) objectMessage.getObject());
50              } else {
51                  logger.warn("Received message is of type " + message.getJMSType()
52                      + ", was expecting ObjectMessage.");
53              }
54          } catch (final JMSException jmse) {
55              logger.error("Exception thrown while processing incoming message.",
56                  jmse);
57          }
58      }
59  
60      /**
61       * Looks up an object from the Context.
62       * @param ctx The Context.
63       * @param name The name of the object to locate.
64       * @return The object.
65       * @throws NamingException if an error occurs.
66       */
67      protected Object lookup(final Context ctx, final String name) throws NamingException {
68          try {
69              return ctx.lookup(name);
70          } catch (final NameNotFoundException e) {
71              logger.error("Could not find name [" + name + "].");
72              throw e;
73          }
74      }
75  
76  }