View Javadoc

1   /*
2    * $Id: RmiMessageDispatcher.java 7976 2007-08-21 14:26:13Z dirk.olmes $
3    * --------------------------------------------------------------------------------------
4    * Copyright (c) MuleSource, Inc.  All rights reserved.  http://www.mulesource.com
5    *
6    * The software in this package is published under the terms of the CPAL v1.0
7    * license, a copy of which has been included with this distribution in the
8    * LICENSE.txt file.
9    */
10  
11  package org.mule.providers.rmi;
12  
13  import org.mule.impl.MuleMessage;
14  import org.mule.providers.AbstractMessageDispatcher;
15  import org.mule.umo.UMOEvent;
16  import org.mule.umo.UMOMessage;
17  import org.mule.umo.endpoint.UMOImmutableEndpoint;
18  import org.mule.umo.transformer.TransformerException;
19  
20  import java.lang.reflect.Method;
21  import java.rmi.RMISecurityManager;
22  import java.rmi.Remote;
23  import java.util.Collections;
24  
25  /**
26   * <code>RmiMessageDispatcher</code> will send transformed mule events over
27   * RMI-JRMP.
28   */
29  public class RmiMessageDispatcher extends AbstractMessageDispatcher
30  {
31      private final RmiConnector connector;
32      protected volatile Remote remoteObject;
33      protected volatile Method invokedMethod;
34  
35      public RmiMessageDispatcher(UMOImmutableEndpoint endpoint)
36      {
37          super(endpoint);
38          this.connector = (RmiConnector)endpoint.getConnector();
39      }
40  
41      protected void doConnect() throws Exception
42      {
43          if (remoteObject == null)
44          {
45              // Shouldn't all this be in the connector?
46              String rmiPolicyPath = connector.getSecurityPolicy();
47              System.setProperty("java.security.policy", rmiPolicyPath);
48  
49              // Set security manager
50              if (System.getSecurityManager() == null)
51              {
52                  System.setSecurityManager(new RMISecurityManager());
53              }
54  
55              remoteObject = connector.getRemoteObject(endpoint);
56          }
57      }
58  
59      protected void doDisconnect() throws Exception
60      {
61          remoteObject = null;
62          invokedMethod = null;
63      }
64  
65      private Object[] getArgs(UMOEvent event) throws TransformerException
66      {
67          Object payload = event.getTransformedMessage();
68          if (payload instanceof Object[])
69          {
70              return (Object[])payload;
71          }
72          else
73          {
74              return new Object[]{payload};
75          }
76      }
77  
78      /*
79       * (non-Javadoc)
80       * 
81       * @see org.mule.umo.provider.UMOConnectorSession#dispatch(org.mule.umo.UMOEvent)
82       */
83      protected void doDispatch(UMOEvent event) throws Exception
84      {
85          Object[] arguments = getArgs(event);
86          if (invokedMethod == null)
87          {
88              invokedMethod = connector.getMethodObject(remoteObject, event);
89          }
90          invokedMethod.invoke(remoteObject, arguments);
91      }
92  
93      /*
94       * (non-Javadoc)
95       * 
96       * @see org.mule.umo.provider.UMOConnectorSession#send(org.mule.umo.UMOEvent)
97       */
98      public UMOMessage doSend(UMOEvent event) throws Exception
99      {
100         if (invokedMethod == null)
101         {
102             invokedMethod = connector.getMethodObject(remoteObject, event);
103         }
104 
105         Object[] arguments = getArgs(event);
106         Object result = invokedMethod.invoke(remoteObject, arguments);
107 
108         if (result == null)
109         {
110             return null;
111         }
112         else
113         {
114             return new MuleMessage(connector.getMessageAdapter(result).getPayload(), Collections.EMPTY_MAP);
115         }
116     }
117 
118     /**
119      * Make a specific request to the underlying transport
120      * 
121      * @param endpoint the endpoint to use when connecting to the resource
122      * @param timeout the maximum time the operation should block before returning.
123      *            The call should return immediately if there is data available. If
124      *            no data becomes available before the timeout elapses, null will be
125      *            returned
126      * @return the result of the request wrapped in a UMOMessage object. Null will be
127      *         returned if no data was avaialable
128      * @throws Exception if the call to the underlying protocal cuases an exception
129      */
130     protected UMOMessage doReceive(long timeout) throws Exception
131     {
132         throw new UnsupportedOperationException("doReceive");
133     }
134 
135     protected void doDispose()
136     {
137         // template method
138     }
139 }