1 package org.apache.onami.persist;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import javax.inject.Inject;
23 import javax.inject.Singleton;
24 import javax.persistence.EntityTransaction;
25
26 import static org.apache.onami.persist.Preconditions.checkNotNull;
27
28 /**
29 * Factory for transaction facades in case of resource local transactions.
30 */
31 @Singleton
32 class ResourceLocalTransactionFacadeFactory
33 implements TransactionFacadeFactory
34 {
35
36 /**
37 * The provider for the entity manager.
38 */
39 private final EntityManagerProvider emProvider;
40
41 /**
42 * Constructor.
43 *
44 * @param emProvider the provider for the entity manager
45 */
46 @Inject
47 ResourceLocalTransactionFacadeFactory( EntityManagerProvider emProvider )
48 {
49 this.emProvider = checkNotNull( emProvider, "emProvider is mandatory!" );
50 }
51
52 /**
53 * {@inheritDoc}
54 */
55 // @Override
56 public TransactionFacade createTransactionFacade()
57 {
58 final EntityTransaction txn = emProvider.get().getTransaction();
59 if ( txn.isActive() )
60 {
61 return new Inner( txn );
62 }
63 else
64 {
65 return new Outer( txn );
66 }
67 }
68
69 /**
70 * TransactionFacade representing an inner (nested) transaction.
71 * Starting and committing a transaction has no effect.
72 * This facade will set the rollbackOnly flag in case of a roll back.
73 */
74 private static class Inner
75 implements TransactionFacade
76 {
77 private final EntityTransaction txn;
78
79 Inner( EntityTransaction txn )
80 {
81 this.txn = checkNotNull( txn, "txn is mandatory!" );
82 }
83
84 /**
85 * {@inheritDoc}
86 */
87 // @Override
88 public void begin()
89 {
90 // Do nothing
91 }
92
93 /**
94 * {@inheritDoc}
95 */
96 // @Override
97 public void commit()
98 {
99 // Do nothing
100 }
101
102 /**
103 * {@inheritDoc}
104 */
105 // @Override
106 public void rollback()
107 {
108 txn.setRollbackOnly();
109 }
110 }
111
112 /**
113 * TransactionFacade representing an outer transaction.
114 * This facade starts and ends the transaction.
115 * If an inner transaction has set the rollbackOnly flag the transaction will be rolled back in any case.
116 */
117 private static class Outer
118 implements TransactionFacade
119 {
120 private final EntityTransaction txn;
121
122 /**
123 * {@inheritDoc}
124 */
125 Outer( EntityTransaction txn )
126 {
127 this.txn = checkNotNull( txn, "txn is mandatory!" );
128 }
129
130 /**
131 * {@inheritDoc}
132 */
133 // @Override
134 public void begin()
135 {
136 txn.begin();
137 }
138
139 /**
140 * {@inheritDoc}
141 */
142 // @Override
143 public void commit()
144 {
145 if ( txn.getRollbackOnly() )
146 {
147 txn.rollback();
148 }
149 else
150 {
151 txn.commit();
152 }
153 }
154
155 /**
156 * {@inheritDoc}
157 */
158 // @Override
159 public void rollback()
160 {
161 txn.rollback();
162 }
163 }
164
165 }