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Java > Open Source Codes > org > apache > ojb > odmg > TransactionAware


1 package org.apache.ojb.odmg;
2
3 /* Copyright 2002-2005 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 java.io.Serializable JavaDoc;
19
20 /**
21  *
22  * TransactionAware is an interface that can be implemented
23  * to provide hooks into the Transaction interface provided
24  * by ObJectRelationalBridge.
25  * Only objects which have a write lock acquired on them can
26  * participate in a transaction.
27  * To kill a transaction, implement beforeCommit() and throw
28  * a TransactionAbortedException. This will force the entire
29  * transaction to rollback.
30  *
31  * To rebuild an object after a rollback use the afterAbort()
32  * call. This is a good place to populate transient or other
33  * variables.
34  *
35  * beforeAbort and afterCommit are there for informational
36  * purposes.
37  *
38  * Here are some common ways you can expect this interface
39  * to be called:
40  *
41  * Sucessful commit:
42  * beforeCommit()
43  * afterCommit()
44  *
45  * Transaction Failure (1):
46  * beforeCommit()
47  * beforeAbort()
48  * afterAbort()
49  *
50  * Transaction Failure (2):
51  * beforeAbort()
52  * afterAbort()
53  *
54  * Commits and Aborts aren't directly provided to TransactionAware classes.
55  * The idea is that Transactions are difficult to handle, and most of it
56  * will be handled by ObjectSnapshot. However, you use TransactionAware
57  * to do one of two things, kill a transaction from happening, and clean
58  * up after a rollback.
59  *
60  * @version $Id: TransactionAware.java,v 1.6.2.1 2005/12/21 22:29:21 tomdz Exp $
61  */
62 public interface TransactionAware extends Serializable JavaDoc
63 {
64     static final long serialVersionUID = 3690863289834166023L; /**
65      *
66      * beforeCommit will give an object a chance to kill a
67      * transaction before it is committed.
68      * To kill a transaction, throw a new TransactionAbortedException.
69      *
70      */
71     public void beforeCommit() throws org.odmg.TransactionAbortedException;
72
73     /**
74      *
75      * afterCommit is called only after a successful commit has taken
76      * place.
77      *
78      */
79     public void afterCommit();
80
81     /**
82      *
83      * beforeAbort is called before a transaction is aborted.
84      *
85      */
86     public void beforeAbort();
87
88     /**
89      *
90      * afterAbort will be called after a transaction has been aborted.
91      * The values of fields which get persisted will have changed to
92      * what they were at the begining of the transaction. This method
93      * should be overridden to reset any transient or non-persistent
94      * fields.
95      *
96      */
97     public void afterAbort();
98 }
99
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