1 /*
2 * Copyright 2002-2014 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.jpa;
18
19 import java.io.Serializable;
20 import java.sql.SQLException;
21 import javax.persistence.EntityManager;
22 import javax.persistence.PersistenceException;
23
24 import org.springframework.dao.DataAccessException;
25 import org.springframework.jdbc.datasource.ConnectionHandle;
26 import org.springframework.transaction.InvalidIsolationLevelException;
27 import org.springframework.transaction.TransactionDefinition;
28 import org.springframework.transaction.TransactionException;
29
30 /**
31 * Default implementation of the {@link JpaDialect} interface.
32 * Used as default dialect by {@link JpaTransactionManager}.
33 *
34 * <p>Simply begins a standard JPA transaction in {@link #beginTransaction} and
35 * performs standard exception translation through {@link EntityManagerFactoryUtils}.
36 *
37 * <p><b>NOTE: Spring's JPA support requires JPA 2.0 or higher, as of Spring 4.0.</b>
38 *
39 * @author Juergen Hoeller
40 * @since 2.0
41 * @see JpaTransactionManager#setJpaDialect
42 */
43 @SuppressWarnings("serial")
44 public class DefaultJpaDialect implements JpaDialect, Serializable {
45
46 /**
47 * This implementation invokes the standard JPA {@code Transaction.begin}
48 * method. Throws an InvalidIsolationLevelException if a non-default isolation
49 * level is set.
50 * <p>This implementation does not return any transaction data Object, since there
51 * is no state to be kept for a standard JPA transaction. Hence, subclasses do not
52 * have to care about the return value ({@code null}) of this implementation
53 * and are free to return their own transaction data Object.
54 * @see javax.persistence.EntityTransaction#begin
55 * @see org.springframework.transaction.InvalidIsolationLevelException
56 * @see #cleanupTransaction
57 */
58 @Override
59 public Object beginTransaction(EntityManager entityManager, TransactionDefinition definition)
60 throws PersistenceException, SQLException, TransactionException {
61
62 if (definition.getIsolationLevel() != TransactionDefinition.ISOLATION_DEFAULT) {
63 throw new InvalidIsolationLevelException(getClass().getSimpleName() +
64 " does not support custom isolation levels due to limitations in standard JPA. " +
65 "Specific arrangements may be implemented in custom JpaDialect variants.");
66 }
67 entityManager.getTransaction().begin();
68 return null;
69 }
70
71 @Override
72 public Object prepareTransaction(EntityManager entityManager, boolean readOnly, String name)
73 throws PersistenceException {
74
75 return null;
76 }
77
78 /**
79 * This implementation does nothing, since the default {@code beginTransaction}
80 * implementation does not require any cleanup.
81 * @see #beginTransaction
82 */
83 @Override
84 public void cleanupTransaction(Object transactionData) {
85 }
86
87 /**
88 * This implementation always returns {@code null},
89 * indicating that no JDBC Connection can be provided.
90 */
91 @Override
92 public ConnectionHandle getJdbcConnection(EntityManager entityManager, boolean readOnly)
93 throws PersistenceException, SQLException {
94
95 return null;
96 }
97
98 /**
99 * This implementation does nothing, assuming that the Connection
100 * will implicitly be closed with the EntityManager.
101 * <p>If the JPA implementation returns a Connection handle that it expects
102 * the application to close after use, the dialect implementation needs to invoke
103 * {@code Connection.close()} (or some other method with similar effect) here.
104 * @see java.sql.Connection#close()
105 */
106 @Override
107 public void releaseJdbcConnection(ConnectionHandle conHandle, EntityManager em)
108 throws PersistenceException, SQLException {
109 }
110
111
112 //-----------------------------------------------------------------------------------
113 // Hook for exception translation (used by JpaTransactionManager)
114 //-----------------------------------------------------------------------------------
115
116 /**
117 * This implementation delegates to EntityManagerFactoryUtils.
118 * @see EntityManagerFactoryUtils#convertJpaAccessExceptionIfPossible
119 */
120 @Override
121 public DataAccessException translateExceptionIfPossible(RuntimeException ex) {
122 return EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(ex);
123 }
124
125 }