org.springframework.orm.jpa

Class DefaultJpaDialect

java.lang.Object

org.springframework.orm.jpa.DefaultJpaDialect

All Implemented Interfaces:

Serializable, PersistenceExceptionTranslator, JpaDialect

Direct Known Subclasses:

EclipseLinkJpaDialect, HibernateJpaDialect, OpenJpaDialect

public class DefaultJpaDialect
extends Object
implements JpaDialect, Serializable

Default implementation of the JpaDialect interface. Used as default dialect by JpaTransactionManager.

Simply begins a standard JPA transaction in beginTransaction(javax.persistence.EntityManager, org.springframework.transaction.TransactionDefinition) and performs standard exception translation through EntityManagerFactoryUtils.

NOTE: Spring's JPA support requires JPA 2.0 or higher, as of Spring 4.0.

Since:

2.0

Author:

Juergen Hoeller

See Also:

JpaTransactionManager.setJpaDialect(org.springframework.orm.jpa.JpaDialect), Serialized Form

Constructor Summary

Constructors

Constructor and Description
DefaultJpaDialect()

Method Summary

Modifier and Type	Method and Description
Object	beginTransaction(EntityManager entityManager, TransactionDefinition definition) This implementation invokes the standard JPA Transaction.begin method.
void	cleanupTransaction(Object transactionData) This implementation does nothing, since the default beginTransaction implementation does not require any cleanup.
ConnectionHandle	getJdbcConnection(EntityManager entityManager, boolean readOnly) This implementation always returns null, indicating that no JDBC Connection can be provided.
Object	prepareTransaction(EntityManager entityManager, boolean readOnly, String name) Prepare a JPA transaction, applying the specified semantics.
void	releaseJdbcConnection(ConnectionHandle conHandle, EntityManager em) This implementation does nothing, assuming that the Connection will implicitly be closed with the EntityManager.
DataAccessException	translateExceptionIfPossible(RuntimeException ex) This implementation delegates to EntityManagerFactoryUtils.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DefaultJpaDialect

public DefaultJpaDialect()

Method Detail

beginTransaction

public Object beginTransaction(EntityManager entityManager,
                               TransactionDefinition definition)
                        throws PersistenceException,
                               SQLException,
                               TransactionException

This implementation invokes the standard JPA Transaction.begin method. Throws an InvalidIsolationLevelException if a non-default isolation level is set.

This implementation does not return any transaction data Object, since there is no state to be kept for a standard JPA transaction. Hence, subclasses do not have to care about the return value (null) of this implementation and are free to return their own transaction data Object.

Specified by:

beginTransaction in interface JpaDialect

Parameters:

entityManager - the EntityManager to begin a JPA transaction on

definition - the Spring transaction definition that defines semantics

Returns:

an arbitrary object that holds transaction data, if any (to be passed into JpaDialect.cleanupTransaction(java.lang.Object)). May implement the SavepointManager interface.

Throws:

PersistenceException - if thrown by JPA methods

SQLException - if thrown by JDBC methods

TransactionException - in case of invalid arguments

See Also:

EntityTransaction.begin(), InvalidIsolationLevelException, cleanupTransaction(java.lang.Object)

prepareTransaction

public Object prepareTransaction(EntityManager entityManager,
                                 boolean readOnly,
                                 String name)
                          throws PersistenceException

Description copied from interface: JpaDialect

Prepare a JPA transaction, applying the specified semantics. Called by EntityManagerFactoryUtils when enlisting an EntityManager in a JTA transaction or a locally joined transaction (e.g. after upgrading an unsynchronized EntityManager to a synchronized one).

An implementation can apply the read-only flag as flush mode. In that case, a transaction data object can be returned that holds the previous flush mode (and possibly other data), to be reset in cleanupTransaction.

Implementations can also use the Spring transaction name to optimize for specific data access use cases (effectively using the current transaction name as use case identifier).

Specified by:

prepareTransaction in interface JpaDialect

Parameters:

entityManager - the EntityManager to begin a JPA transaction on

readOnly - whether the transaction is supposed to be read-only

name - the name of the transaction (if any)

Returns:

an arbitrary object that holds transaction data, if any (to be passed into cleanupTransaction)

Throws:

PersistenceException - if thrown by JPA methods

See Also:

JpaDialect.cleanupTransaction(java.lang.Object)

cleanupTransaction

public void cleanupTransaction(Object transactionData)

This implementation does nothing, since the default beginTransaction implementation does not require any cleanup.

Specified by:

cleanupTransaction in interface JpaDialect

Parameters:

transactionData - arbitrary object that holds transaction data, if any (as returned by beginTransaction or prepareTransaction)

See Also:

beginTransaction(javax.persistence.EntityManager, org.springframework.transaction.TransactionDefinition)

getJdbcConnection

public ConnectionHandle getJdbcConnection(EntityManager entityManager,
                                          boolean readOnly)
                                   throws PersistenceException,
                                          SQLException

This implementation always returns null, indicating that no JDBC Connection can be provided.

Specified by:

getJdbcConnection in interface JpaDialect

Parameters:

entityManager - the current JPA EntityManager

readOnly - whether the Connection is only needed for read-only purposes

Returns:

a handle for the JDBC Connection, to be passed into releaseJdbcConnection, or null if no JDBC Connection can be retrieved

Throws:

PersistenceException - if thrown by JPA methods

SQLException - if thrown by JDBC methods

See Also:

JpaDialect.releaseJdbcConnection(org.springframework.jdbc.datasource.ConnectionHandle, javax.persistence.EntityManager), ConnectionHandle.getConnection(), SimpleConnectionHandle, JpaTransactionManager.setDataSource(javax.sql.DataSource), NativeJdbcExtractor

releaseJdbcConnection

public void releaseJdbcConnection(ConnectionHandle conHandle,
                                  EntityManager em)
                           throws PersistenceException,
                                  SQLException

This implementation does nothing, assuming that the Connection will implicitly be closed with the EntityManager.

If the JPA implementation returns a Connection handle that it expects the application to close after use, the dialect implementation needs to invoke Connection.close() (or some other method with similar effect) here.

Specified by:

releaseJdbcConnection in interface JpaDialect

Parameters:

conHandle - the JDBC Connection handle to release

em - the current JPA EntityManager

Throws:

PersistenceException - if thrown by JPA methods

SQLException - if thrown by JDBC methods

See Also:

Connection.close()

translateExceptionIfPossible

public DataAccessException translateExceptionIfPossible(RuntimeException ex)

This implementation delegates to EntityManagerFactoryUtils.

Specified by:

translateExceptionIfPossible in interface PersistenceExceptionTranslator

Parameters:

ex - a RuntimeException to translate

Returns:

the corresponding DataAccessException (or null if the exception could not be translated, as in this case it may result from user code rather than from an actual persistence problem)

See Also:

EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(java.lang.RuntimeException)