org.springframework.orm.jdo

Class DefaultJdoDialect

java.lang.Object

org.springframework.orm.jdo.DefaultJdoDialect

All Implemented Interfaces:

PersistenceExceptionTranslator, JdoDialect

public class DefaultJdoDialect
extends Object
implements JdoDialect, PersistenceExceptionTranslator

Default implementation of the JdoDialect interface. As of Spring 4.0, designed for JDO 3.0 (or rather, semantics beyond JDO 3.0). Used as default dialect by JdoTransactionManager.

Simply begins a standard JDO transaction in beginTransaction. Returns a handle for a JDO DataStoreConnection on getJdbcConnection. Calls the corresponding JDO PersistenceManager operation on flush Uses a Spring SQLExceptionTranslator for exception translation, if applicable.

Note that, even with JDO 3.0, vendor-specific subclasses are still necessary for special transaction semantics and more sophisticated exception translation. Furthermore, vendor-specific subclasses are encouraged to expose the native JDBC Connection on getJdbcConnection, rather than JDO 3.0's wrapper handle.

This class also implements the PersistenceExceptionTranslator interface, as autodetected by Spring's PersistenceExceptionTranslationPostProcessor, for AOP-based translation of native exceptions to Spring DataAccessExceptions. Hence, the presence of a standard DefaultJdoDialect bean automatically enables a PersistenceExceptionTranslationPostProcessor to translate JDO exceptions.

Since:

1.1

Author:

Juergen Hoeller

See Also:

setJdbcExceptionTranslator(org.springframework.jdbc.support.SQLExceptionTranslator), JdoTransactionManager.setJdoDialect(org.springframework.orm.jdo.JdoDialect), PersistenceExceptionTranslationPostProcessor

Constructor Summary

Constructors

Constructor and Description
DefaultJdoDialect() Create a new DefaultJdoDialect.
DefaultJdoDialect(Object connectionFactory) Create a new DefaultJdoDialect.

Method Summary

Modifier and Type	Method and Description
Object	beginTransaction(javax.jdo.Transaction transaction, TransactionDefinition definition) This implementation invokes the standard JDO Transaction.begin() method and also Transaction.setIsolationLevel(String) if necessary.
void	cleanupTransaction(Object transactionData) This implementation does nothing, as the default beginTransaction implementation does not require any cleanup.
protected String	extractSqlStringFromException(javax.jdo.JDOException ex) Template method for extracting a SQL String from the given exception.
ConnectionHandle	getJdbcConnection(javax.jdo.PersistenceManager pm, boolean readOnly) This implementation returns a DataStoreConnectionHandle for JDO.
SQLExceptionTranslator	getJdbcExceptionTranslator() Return the JDBC exception translator for this dialect, if any.
protected String	getJdoIsolationLevel(TransactionDefinition definition) Determine the JDO isolation level String to use for the given Spring transaction definition.
void	releaseJdbcConnection(ConnectionHandle conHandle, javax.jdo.PersistenceManager pm) This implementation does nothing, assuming that the Connection will implicitly be closed with the PersistenceManager.
void	setJdbcExceptionTranslator(SQLExceptionTranslator jdbcExceptionTranslator) Set the JDBC exception translator for this dialect.
DataAccessException	translateException(javax.jdo.JDOException ex) This implementation delegates to PersistenceManagerFactoryUtils.
DataAccessException	translateExceptionIfPossible(RuntimeException ex) Implementation of the PersistenceExceptionTranslator interface, as autodetected by Spring's PersistenceExceptionTranslationPostProcessor.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultJdoDialect

public DefaultJdoDialect()

Create a new DefaultJdoDialect.

DefaultJdoDialect

public DefaultJdoDialect(Object connectionFactory)

Create a new DefaultJdoDialect.

Parameters:

connectionFactory - the connection factory of the JDO PersistenceManagerFactory, which is used to initialize the default JDBC exception translator

See Also:

PersistenceManagerFactory.getConnectionFactory(), PersistenceManagerFactoryUtils.newJdbcExceptionTranslator(Object)

Method Detail

setJdbcExceptionTranslator

public void setJdbcExceptionTranslator(SQLExceptionTranslator jdbcExceptionTranslator)

Set the JDBC exception translator for this dialect.

Applied to any SQLException root cause of a JDOException, if specified. The default is to rely on the JDO provider's native exception translation.

Parameters:

jdbcExceptionTranslator - exception translator

See Also:

SQLException, JDOException.getCause(), SQLErrorCodeSQLExceptionTranslator, SQLStateSQLExceptionTranslator

getJdbcExceptionTranslator

public SQLExceptionTranslator getJdbcExceptionTranslator()

Return the JDBC exception translator for this dialect, if any.

beginTransaction

public Object beginTransaction(javax.jdo.Transaction transaction,
                               TransactionDefinition definition)
                        throws javax.jdo.JDOException,
                               SQLException,
                               TransactionException

This implementation invokes the standard JDO Transaction.begin() method and also Transaction.setIsolationLevel(String) if necessary.

Specified by:

beginTransaction in interface JdoDialect

Parameters:

transaction - the JDO transaction to begin

definition - the Spring transaction definition that defines semantics

Returns:

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

Throws:

javax.jdo.JDOException - if thrown by JDO methods

SQLException - if thrown by JDBC methods

TransactionException - in case of invalid arguments

See Also:

Transaction.begin(), InvalidIsolationLevelException

getJdoIsolationLevel

protected String getJdoIsolationLevel(TransactionDefinition definition)

Determine the JDO isolation level String to use for the given Spring transaction definition.

Parameters:

definition - the Spring transaction definition

Returns:

the corresponding JDO isolation level String, or null to indicate that no isolation level should be set explicitly

See Also:

Transaction.setIsolationLevel(String), Constants.TX_SERIALIZABLE, Constants.TX_REPEATABLE_READ, Constants.TX_READ_COMMITTED, Constants.TX_READ_UNCOMMITTED

cleanupTransaction

public void cleanupTransaction(Object transactionData)

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

Specified by:

cleanupTransaction in interface JdoDialect

Parameters:

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

See Also:

beginTransaction(javax.jdo.Transaction, org.springframework.transaction.TransactionDefinition)

getJdbcConnection

public ConnectionHandle getJdbcConnection(javax.jdo.PersistenceManager pm,
                                          boolean readOnly)
                                   throws javax.jdo.JDOException,
                                          SQLException

This implementation returns a DataStoreConnectionHandle for JDO.

NOTE: A JDO DataStoreConnection is always a wrapper, never the native JDBC Connection. If you need access to the native JDBC Connection (or the connection pool handle, to be unwrapped via a Spring NativeJdbcExtractor), override this method to return the native Connection through the corresponding vendor-specific mechanism.

A JDO DataStoreConnection is only "borrowed" from the PersistenceManager: it needs to be returned as early as possible. Effectively, JDO requires the fetched Connection to be closed before continuing PersistenceManager work. For this reason, the exposed ConnectionHandle eagerly releases its JDBC Connection at the end of each JDBC data access operation (that is, on DataSourceUtils.releaseConnection).

Specified by:

getJdbcConnection in interface JdoDialect

Parameters:

pm - the current JDO PersistenceManager

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:

javax.jdo.JDOException - if thrown by JDO methods

SQLException - if thrown by JDBC methods

See Also:

PersistenceManager.getDataStoreConnection(), NativeJdbcExtractor, DataSourceUtils.releaseConnection(java.sql.Connection, javax.sql.DataSource)

releaseJdbcConnection

public void releaseJdbcConnection(ConnectionHandle conHandle,
                                  javax.jdo.PersistenceManager pm)
                           throws javax.jdo.JDOException,
                                  SQLException

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

If the JDO provider returns a Connection handle that it expects the application to close, the dialect needs to invoke Connection.close here.

Specified by:

releaseJdbcConnection in interface JdoDialect

Parameters:

conHandle - the JDBC Connection handle to release

pm - the current JDO PersistenceManager

Throws:

javax.jdo.JDOException - if thrown by JDO methods

SQLException - if thrown by JDBC methods

See Also:

Connection.close()

translateExceptionIfPossible

public DataAccessException translateExceptionIfPossible(RuntimeException ex)

Implementation of the PersistenceExceptionTranslator interface, as autodetected by Spring's PersistenceExceptionTranslationPostProcessor.

Converts the exception if it is a JDOException, using this JdoDialect. Else returns null to indicate an unknown exception.

Specified by:

translateExceptionIfPossible in interface PersistenceExceptionTranslator

Parameters:

ex - a RuntimeException thrown

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 an actual persistence problem)

See Also:

PersistenceExceptionTranslationPostProcessor, translateException(javax.jdo.JDOException)

translateException

public DataAccessException translateException(javax.jdo.JDOException ex)

This implementation delegates to PersistenceManagerFactoryUtils.

Specified by:

translateException in interface JdoDialect

Parameters:

ex - the JDOException thrown

Returns:

the corresponding DataAccessException (must not be null)

See Also:

PersistenceManagerFactoryUtils.convertJdoAccessException(javax.jdo.JDOException)

extractSqlStringFromException

protected String extractSqlStringFromException(javax.jdo.JDOException ex)

Template method for extracting a SQL String from the given exception.

Default implementation always returns null. Can be overridden in subclasses to extract SQL Strings for vendor-specific exception classes.

Parameters:

ex - the JDOException, containing a SQLException

Returns:

the SQL String, or null if none found