TransactionAwareDataSourceConnectionFactory


1   /*
2    * Copyright 2002-2005 the original author or authors.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.springframework.orm.ojb.support;
18  
19  import javax.sql.DataSource  ;
20  
21  import org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy;
22  
23  /**
24   * Subclass of LocalDataSourceConnectionFactory that returns transaction-aware
25   * proxies for all DataSources retrieved by OJB.
26   *
27   * <p>Define the following entry in your OJB.properties to use this connection factory:
28   *
29   * <pre>
30   * ConnectionFactoryClass=org.springframework.orm.ojb.support.TransactionAwareDataSourceConnectionFactory</pre>
31   *
32   * This connection factory allows Spring's OJB access to participate in JDBC-based
33   * transactions managed outside of OJB (for example, by Spring's DataSourceTransactionManager).
34   * This can be convenient if you need a different local transaction strategy for another O/R
35   * mapping tool, for example, but still want OJB access to join into those transactions.
36   *
37   * <p>A further benefit of this factory is that plain PersistenceBrokers
38   * (opened directly via the PersistenceBrokerFactory, outside of Spring's OJB support)
39   * will still participate in active Spring-managed transactions.
40   *
41   * <p>As a further effect, using a transaction-aware DataSource will apply remaining
42   * transaction timeouts to all created JDBC Statements. This means that all operations
43   * performed by OJB will automatically participate in Spring-managed transaction timeouts.
44   * This is even desirable for transactions managed by PersistenceBrokerTransactionManager.
45   *
46   * @author Juergen Hoeller
47   * @since 1.1.4
48   * @see org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy
49   * @see org.springframework.jdbc.datasource.DataSourceTransactionManager
50   * @see org.springframework.orm.ojb.PersistenceBrokerTransactionManager
51   */
52  public class TransactionAwareDataSourceConnectionFactory extends LocalDataSourceConnectionFactory {
53  
54      /**
55       * Return a TransactionAwareDataSourceProxy for the original DataSource
56       * (i.e. the Spring bean with the JCD alias name), provided that it
57       * isn't a TransactionAwareDataSourceProxy already.
58       */
59      protected DataSource   getDataSource(String   jcdAlias) {
60          DataSource   originalDataSource = super.getDataSource(jcdAlias);
61          if (originalDataSource instanceof TransactionAwareDataSourceProxy) {
62              return originalDataSource;
63          }
64          else {
65              return new TransactionAwareDataSourceProxy(originalDataSource);
66          }
67      }
68  
69  }
70
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