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Java > Open Source Codes > org > apache > ojb > broker > transaction > tm > AbstractTransactionManagerFactory


1 package org.apache.ojb.broker.transaction.tm;
2
3 /* Copyright 2004-2005 The Apache Software Foundation
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 import javax.transaction.TransactionManager JavaDoc;
19
20 import org.apache.commons.lang.SystemUtils;
21 import org.apache.ojb.broker.core.NamingLocator;
22 import org.apache.ojb.broker.util.ClassHelper;
23 import org.apache.ojb.broker.util.logging.Logger;
24 import org.apache.ojb.broker.util.logging.LoggerFactory;
25
26 /**
27  * Abstract base class implementation of the {@link TransactionManagerFactory} interface, all
28  * derived classes have to implement method {@link #getLookupInfo()}.
29  *
30  * @author <a HREF="mailto:armin@codeAuLait.de">Armin Waibel</a>
31  * @version $Id: AbstractTransactionManagerFactory.java,v 1.2.2.2 2005/12/21 22:27:48 tomdz Exp $
32  */
33
34 public abstract class AbstractTransactionManagerFactory implements TransactionManagerFactory
35 {
36     private static Logger log = LoggerFactory.getLogger(AbstractTransactionManagerFactory.class);
37
38     /**
39      * Returns "getTransactionManager";
40      */
41     public static String JavaDoc TM_DEFAULT_METHOD_NAME = "getTransactionManager";
42
43
44     private static TransactionManager JavaDoc tm = null;
45
46     /**
47      * Returns an array of possible JNDI lookup / class names for
48      * the {@link javax.transaction.TransactionManager} instance. An array was used
49      * because for different application server versions the
50      * JNDI/class name may change.
51      * <p/>
52      * Expect an [n][3] string array. Following arguments are available:
53      * <ul>
54      * <li>info[i][0] = short description of used TM, e.g. appServer name</li>
55      * <li>info[i][2] = JNDI name to lookup TM or the method name to retrieve TM instance</li>
56      * <li>info[i][3] = if 'null' an JNDI lookup was made with JNDI name set above, if not null
57      * the class name of the TM factory was assumed and the method name set above will be invoked</li>
58      * </ul>
59      * Example:
60      * <p>
61      * {{"JBoss", "java:/TransactionManager", null}};<br/>
62      * In JBoss we lookup the TM via JNDI, so we don't need a TM factory class.
63      * </p>
64      *
65      * <p>
66      * {{"Websphere 4", TM_DEFAULT_METHOD_NAME, "com.ibm.ejs.jts.jta.JTSXA"},<br/>
67      * {"Websphere 5", TM_DEFAULT_METHOD_NAME, "com.ibm.ejs.jts.jta.TransactionManagerFactory"},<br/>
68      * {"Websphere >5", TM_DEFAULT_METHOD_NAME, "com.ibm.ws.Transaction.TransactionManagerFactory"}};<br/>
69      * In Websphere we have to use a TM factory class and obtain the TM via a <em>getTransactionManager()</em>
70      * method call. The TM factory class is varied in different versions.
71      * </p>
72      */
73     public abstract String JavaDoc[][] getLookupInfo();
74
75     /**
76      * @see org.apache.ojb.broker.transaction.tm.TransactionManagerFactory
77      */
78     public synchronized TransactionManager JavaDoc getTransactionManager() throws TransactionManagerFactoryException
79     {
80         if (tm == null)
81         {
82             StringBuffer JavaDoc msg = new StringBuffer JavaDoc();
83             String JavaDoc[][] lookupInfo = getLookupInfo();
84             String JavaDoc EOL = SystemUtils.LINE_SEPARATOR;
85
86             for (int i = 0; i < lookupInfo.length; i++)
87             {
88                 String JavaDoc description = lookupInfo[i][0];
89                 String JavaDoc methodName = lookupInfo[i][1];
90                 String JavaDoc className = lookupInfo[i][2];
91                 try
92                 {
93                     if (className == null)
94                     {
95                         tm = jndiLookup(description, methodName);
96                     }
97                     else
98                     {
99                         tm = instantiateClass(description, className, methodName);
100                     }
101                     msg.append("Successfully requested TM for " + description + EOL);
102                 }
103                 catch (Exception JavaDoc e)
104                 {
105                     if (className == null)
106                         msg.append("Error on TM request for " + description +
107                                 ", using jndi-lookup '" + methodName + "'" + EOL + e.getMessage() + EOL);
108                     else
109                         msg.append("Error on TM request for " + description + ", using method '" +
110                                 methodName + "' for class '" + className + "'" + EOL + e.getMessage() + EOL);
111                 }
112                 if (tm != null) break;
113             }
114             // if we don't get an TM instance throw exception
115 if (tm == null)
116             {
117                 throw new TransactionManagerFactoryException("Can't lookup transaction manager:" + EOL + msg);
118             }
119         }
120         return tm;
121     }
122
123     protected TransactionManager JavaDoc jndiLookup(String JavaDoc description, String JavaDoc methodName)
124     {
125         log.info(description + ", lookup TransactionManager: '" + methodName + "'");
126         return (TransactionManager JavaDoc) NamingLocator.lookup(methodName);
127     }
128
129     protected TransactionManager JavaDoc instantiateClass(String JavaDoc description, String JavaDoc className, String JavaDoc methodName) throws Exception JavaDoc
130     {
131         log.info(description + ", invoke method '"
132                 + methodName + "()' on class " + className);
133         Class JavaDoc tmClass = ClassHelper.getClass(className);
134         return (TransactionManager JavaDoc) tmClass.getMethod(methodName, null).invoke(null, null);
135     }
136 }
137
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