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1 /*
2 * JBoss, Home of Professional Open Source
3 * Copyright 2005, JBoss Inc., and individual contributors as indicated
4 * by the @authors tag. See the copyright.txt in the distribution for a
5 * full listing of individual contributors.
6 *
7 * This is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU Lesser General Public License as
9 * published by the Free Software Foundation; either version 2.1 of
10 * the License, or (at your option) any later version.
11 *
12 * This software is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this software; if not, write to the Free
19 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
21 */
22 package org.jboss.invocation.jrmp.interfaces;
23
24 import java.io.IOException;
25 import java.io.Externalizable;
26 import java.io.ObjectInput;
27 import java.io.ObjectOutput;
28 import java.rmi.ConnectException;
29 import java.rmi.MarshalledObject;
30 import java.rmi.NoSuchObjectException;
31 import java.rmi.RemoteException;
32 import java.rmi.ServerException;
33 import java.rmi.server.RemoteObject;
34 import java.rmi.server.RemoteStub;
35 import javax.transaction.TransactionRolledbackException;
36 import javax.transaction.SystemException;
37
38 import org.jboss.invocation.Invocation;
39 import org.jboss.invocation.Invoker;
40 import org.jboss.invocation.MarshalledInvocation;
41 import org.jboss.tm.TransactionPropagationContextFactory;
42 import org.jboss.tm.TransactionPropagationContextUtil;
43
44 /**
45 * JRMPInvokerProxy, local to the proxy and is capable of delegating to
46 * the JRMP implementations
47 *
48 * @author <a href="mailto:marc.fleury@jboss.org">Marc Fleury</a>
49 * @author <a href="mailto:scott.stark@jboss.org">Scott Stark</a>
50 * @version $Revision: 37459 $
51 */
52 public class JRMPInvokerProxy
53 implements Invoker, Externalizable
54 {
55 /** Serial Version Identifier. @since 1.7.2.4 */
56 private static final long serialVersionUID = -3713605626489646730L;
57 // Attributes ----------------------------------------------------
58
59 // Invoker to the remote JMX node
60 protected Invoker remoteInvoker;
61
62 /**
63 * max retries on a ConnectException.
64 */
65 public static int MAX_RETRIES = 10;
66
67 /**
68 * Exposed for externalization.
69 */
70 public JRMPInvokerProxy()
71 {
72 super();
73 }
74
75 /**
76 * Create a new Proxy.
77 *
78 * @param container The remote interface of the container invoker of the
79 * container we proxy for.
80 */
81 public JRMPInvokerProxy(final Invoker remoteInvoker)
82 {
83 this.remoteInvoker = remoteInvoker;
84 }
85
86 /**
87 * The name of of the server.
88 */
89 public String getServerHostName() throws Exception
90 {
91 return remoteInvoker.getServerHostName();
92 }
93
94 /**
95 * ???
96 *
97 * @todo: MOVE TO TRANSACTION
98 *
99 * @return the transaction propagation context of the transaction
100 * associated with the current thread.
101 * Returns <code>null</code> if the transaction manager was never
102 * set, or if no transaction is associated with the current thread.
103 */
104 public Object getTransactionPropagationContext()
105 throws SystemException
106 {
107 TransactionPropagationContextFactory tpcFactory = TransactionPropagationContextUtil.getTPCFactoryClientSide();
108 return (tpcFactory == null) ? null : tpcFactory.getTransactionPropagationContext();
109 }
110
111 /**
112 * The invocation on the delegate, calls the right invoker. Remote if we are remote,
113 * local if we are local.
114 * @todo Shouldn't we unwrap _ALL_ RemoteExceptions?
115 */
116 public Object invoke(Invocation invocation)
117 throws Exception
118 {
119 // We are going to go through a Remote invocation, switch to a Marshalled Invocation
120 MarshalledInvocation mi = new MarshalledInvocation(invocation);
121
122 // Set the transaction propagation context
123 // @todo: MOVE TO TRANSACTION
124 mi.setTransactionPropagationContext(getTransactionPropagationContext());
125
126 // RMI seems to make a connection per invocation.
127 // If too many clients are making an invocation
128 // at same time, ConnectionExceptions happen
129 for (int i = 0; i < MAX_RETRIES; i++)
130 {
131 try
132 {
133 MarshalledObject result = (MarshalledObject) remoteInvoker.invoke(mi);
134 return result.get();
135 }
136 catch (ConnectException ce)
137 {
138 if (i + 1 < MAX_RETRIES)
139 {
140 Thread.sleep(1);
141 continue;
142 }
143 throw ce;
144 }
145 catch (ServerException ex)
146 {
147 // Suns RMI implementation wraps NoSuchObjectException in
148 // a ServerException. We cannot have that if we want
149 // to comply with the spec, so we unwrap here.
150 if (ex.detail instanceof NoSuchObjectException)
151 {
152 throw (NoSuchObjectException) ex.detail;
153 }
154 if (ex.detail instanceof TransactionRolledbackException)
155 {
156 throw (TransactionRolledbackException) ex.detail;
157 }
158 if (ex.detail instanceof RemoteException)
159 {
160 throw (RemoteException) ex.detail;
161 }
162 throw ex;
163 }
164 }
165 throw new Exception("Unreachable statement");
166 }
167
168 /**
169 * Externalize this instance and handle obtaining the remoteInvoker stub
170 */
171 public void writeExternal(final ObjectOutput out)
172 throws IOException
173 {
174 /** We need to handle obtaining the RemoteStub for the remoteInvoker
175 * since this proxy may be serialized in contexts that are not JRMP
176 * aware.
177 */
178 if( remoteInvoker instanceof RemoteStub )
179 {
180 out.writeObject(remoteInvoker);
181 }
182 else
183 {
184 Object replacement = RemoteObject.toStub(remoteInvoker);
185 out.writeObject(replacement);
186 }
187 }
188
189 /**
190 * Un-externalize this instance.
191 *
192 */
193 public void readExternal(final ObjectInput in)
194 throws IOException, ClassNotFoundException
195 {
196 remoteInvoker = (Invoker) in.readObject();
197 }
198 }
199