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Java > Open Source Codes > org > apache > ojb > otm > transaction > LocalTransactionFactory


1 package org.apache.ojb.otm.transaction;
2
3 /* Copyright 2003-2005 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 org.apache.ojb.broker.PBKey;
19 import org.apache.ojb.otm.OTMConnection;
20 import org.apache.ojb.otm.core.BaseConnection;
21 import org.apache.ojb.otm.core.Transaction;
22 import org.apache.ojb.otm.core.TransactionException;
23
24 import java.util.HashMap JavaDoc;
25
26 /**
27  *
28  * Factory for local transactions. Each OTMConnection is associated with exactly one transaction.
29  *
30  * @author <a HREF="mailto:rraghuram@hotmail.com">Raghu Rajah</a>
31  *
32  */
33 public class LocalTransactionFactory implements TransactionFactory
34 {
35
36     private HashMap JavaDoc _transactionMap;
37
38     public LocalTransactionFactory ()
39     {
40         _transactionMap = new HashMap JavaDoc();
41     }
42
43     /**
44      * @see org.apache.ojb.otm.transaction.TransactionFactory#getTransactionForConnection(OTMConnection)
45      */
46     public Transaction getTransactionForConnection (OTMConnection connection)
47     {
48         if (!(connection instanceof BaseConnection))
49         {
50             StringBuffer JavaDoc msg = new StringBuffer JavaDoc();
51             msg.append("Unknown connection type: ");
52             if (connection != null)
53                 msg.append(connection.getClass().getName());
54             else
55                 msg.append(" null. Make sure you pass a non-null OTMConnection to this method. An OTMConnection can be acquired by calling acquireConnection (PBKey pbKey)");
56             throw new TransactionFactoryException(msg.toString());
57         }
58
59         Transaction tx = (Transaction) _transactionMap.get(connection);
60         if (tx == null)
61         {
62             tx = new Transaction();
63             _transactionMap.put(connection, tx);
64         }
65         // ensure that this connection is registered into this transaction
66 tx.registerConnection(connection);
67         return tx;
68     }
69
70
71     /**
72      * @see org.apache.ojb.otm.transaction.TransactionFactory#acquireConnection(PBKey)
73      */
74     public OTMConnection acquireConnection (PBKey pbKey)
75     {
76         OTMConnection newConnection = new LocalConnection(pbKey);
77         // Ensure the transaction is established for this connection.
78 getTransactionForConnection(newConnection);
79         return newConnection;
80     }
81
82     /**
83      *
84      * Represents a local connection. This is a private static inner class to restrict visibility
85      * to others.
86      *
87      * @author <a HREF="mailto:rraghuram@hotmail.com">Raghu Rajah</a>
88      *
89      */
90     private static class LocalConnection extends BaseConnection
91     {
92         public LocalConnection (PBKey pbKey)
93         {
94             super(pbKey);
95         }
96
97
98         /**
99          * @see org.apache.ojb.otm.core.BaseConnection#transactionBegin()
100          */
101         public void transactionBegin() throws TransactionException
102         {
103             getKernelBroker().beginTransaction();
104         }
105         
106         /**
107          * @see org.apache.ojb.otm.core.BaseConnection#transactionPrepare()
108          */
109         public void transactionPrepare() throws TransactionException
110         {
111             // Nothing to do!
112 }
113
114         /**
115          * @see org.apache.ojb.otm.core.BaseConnection#transactionCommit()
116          */
117         public void transactionCommit() throws TransactionException
118         {
119             getKernelBroker().commitTransaction();
120         }
121
122         /**
123          * @see org.apache.ojb.otm.core.BaseConnection#transactionRollback()
124          */
125         public void transactionRollback() throws TransactionException
126         {
127             getKernelBroker().abortTransaction();
128         }
129
130     }
131 }
132
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