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Java > Open Source Codes > org > objectweb > easybeans > transaction > interceptors > BMTTransactionInterceptor


1 /**
2  * EasyBeans
3  * Copyright (C) 2006 Bull S.A.S.
4  * Contact: easybeans@objectweb.org
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
19  * USA
20  *
21  * --------------------------------------------------------------------------
22  * $Id: BMTTransactionInterceptor.java 9 2006-02-19 18:53:32Z benoitf $
23  * --------------------------------------------------------------------------
24  */
25
26 package org.objectweb.easybeans.transaction.interceptors;
27
28 import javax.ejb.EJBException JavaDoc;
29 import javax.transaction.InvalidTransactionException JavaDoc;
30 import javax.transaction.SystemException JavaDoc;
31 import javax.transaction.Transaction JavaDoc;
32
33 import org.objectweb.easybeans.api.EasyBeansInvocationContext;
34 import org.objectweb.easybeans.log.JLog;
35 import org.objectweb.easybeans.log.JLogFactory;
36
37 /**
38  * Defines an interceptor for method that are in Bean managed mode and then in Bean Managed Transaction.
39  * @author Florent Benoit
40  */
41 public class BMTTransactionInterceptor extends AbsTransactionInterceptor {
42
43     /**
44      * Logger.
45      */
46     private JLog logger = JLogFactory.getLog(BMTTransactionInterceptor.class);
47
48     /**
49      * Constructor.<br>
50      * Acquire the transaction manager.
51      */
52     public BMTTransactionInterceptor() {
53         super();
54     }
55
56     /**
57      * Execute transaction as specified for BMT.
58      * @param invocationContext context with useful attributes on the current
59      * invocation
60      * @return result of the next invocation (to chain interceptors)
61      * @throws Exception if interceptor fails
62      * @see <a HREF="http://www.jcp.org/en/jsr/detail?id=220">EJB 3.0
63      * specification ?12.6.1</a>
64      */
65     @Override JavaDoc
66     public Object JavaDoc intercept(final EasyBeansInvocationContext invocationContext) throws Exception JavaDoc {
67         logger.debug("Calling BMT TX interceptor");
68
69         // Get current transaction
70 Transaction JavaDoc transaction;
71         try {
72             transaction = getTransactionManager().getTransaction();
73         } catch (SystemException JavaDoc se) {
74             throw new EJBException JavaDoc("Cannot get the current transaction on transaction manager.", se);
75         }
76
77         logger.debug("Transaction found = {0}", transaction);
78
79         /*
80          * When a client invokes a business method via one of the enterprise
81          * bean?s client view interfaces, the container suspends any transaction
82          * that may be associated with the client request. If there is a
83          * transaction associated with the instance (this would happen if a
84          * stateful session bean instance started the transaction in some
85          * previous business method), the container associates the method
86          * execution with this transaction. If there are interceptor methods
87          * associated with the bean instances, these actions are taken before
88          * the interceptor methods are invoked.
89          */
90
91         Transaction JavaDoc suspendedTransaction = null;
92         if (transaction != null) {
93             try {
94                 logger.debug("Suspending transaction {0}", transaction);
95                 suspendedTransaction = getTransactionManager().suspend();
96             } catch (SystemException JavaDoc se) {
97                 throw new EJBException JavaDoc("Cannot call suspend() on the transaction manager.", se);
98             }
99         }
100
101
102         try {
103             return invocationContext.proceed();
104         } finally {
105
106             /*
107              * The container resumes the suspended association when the business
108              * method has completed.
109              */
110             if (suspendedTransaction != null) {
111
112                 logger.debug("Resuming transaction {0}", transaction);
113
114                 try {
115                     getTransactionManager().resume(suspendedTransaction);
116                 } catch (InvalidTransactionException JavaDoc ite) {
117                     throw new EJBException JavaDoc(
118                             "Cannot call resume() on the given transaction. There is an invalid transaction", ite);
119                 } catch (IllegalStateException JavaDoc ise) {
120                     throw new EJBException JavaDoc(
121                             "Cannot call resume() on the given transaction. There is another associated transaction",
122                             ise);
123                 } catch (SystemException JavaDoc se) {
124                     throw new EJBException JavaDoc("Cannot call resume() on the given transaction. Unexpected error condition",
125                             se);
126                 }
127             }
128         }
129     }
130
131 }
132
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