public class

DefaultJdoDialect

extends Object
implements PersistenceExceptionTranslator JdoDialect
java.lang.Object
   ↳ org.springframework.orm.jdo.DefaultJdoDialect

Class Overview

Default implementation of the JdoDialect interface. Updated to build on JDO 2.0 or higher, as of Spring 2.5. Used as default dialect by JdoAccessor and JdoTransactionManager.

Simply begins a standard JDO transaction in beginTransaction. Returns a handle for a JDO2 DataStoreConnection on getJdbcConnection. Calls the corresponding JDO2 PersistenceManager operation on flush Ignores a given query timeout in applyQueryTimeout. Uses a Spring SQLExceptionTranslator for exception translation, if applicable.

Note that, even with JDO2, 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 JDO2'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.

See Also

Summary

Fields
protected final Log logger
Public Constructors
DefaultJdoDialect()
Create a new DefaultJdoDialect.
Public Methods
void applyQueryTimeout(Query query, int remainingTimeInSeconds)
This implementation applies a JDO 3.0 query timeout, if available.
Object beginTransaction(Transaction transaction, TransactionDefinition definition)
This implementation invokes the standard JDO Transaction.begin method.
void cleanupTransaction(Object transactionData)
This implementation does nothing, as the default beginTransaction implementation does not require any cleanup.
ConnectionHandle getJdbcConnection(PersistenceManager pm, boolean readOnly)
This implementation returns a DataStoreConnectionHandle for JDO2, which will also work on JDO1 until actually accessing the JDBC Connection.
SQLExceptionTranslator getJdbcExceptionTranslator()
Return the JDBC exception translator for this dialect, if any.
void releaseJdbcConnection(ConnectionHandle conHandle, 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(JDOException ex)
This implementation delegates to PersistenceManagerFactoryUtils.
DataAccessException translateExceptionIfPossible(RuntimeException ex)
Implementation of the PersistenceExceptionTranslator interface, as autodetected by Spring's PersistenceExceptionTranslationPostProcessor.
Protected Methods
String extractSqlStringFromException(JDOException ex)
Template method for extracting a SQL String from the given exception.
[Expand]
Inherited Methods
From class java.lang.Object
From interface org.springframework.dao.support.PersistenceExceptionTranslator
From interface org.springframework.orm.jdo.JdoDialect

Fields

protected final Log logger

Public Constructors

public DefaultJdoDialect ()

Create a new DefaultJdoDialect.

Public Methods

public void applyQueryTimeout (Query query, int remainingTimeInSeconds)

This implementation applies a JDO 3.0 query timeout, if available. Otherwise, it sets the JPA 2.0 query hints "javax.persistence.lock.timeout" and "javax.persistence.query.timeout", assuming that JDO providers are often JPA providers as well.

Parameters
query the JDO query object to apply the timeout to
remainingTimeInSeconds the timeout value (seconds) to apply
Throws
JDOException

public Object beginTransaction (Transaction transaction, TransactionDefinition definition)

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

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
JDOException
SQLException
TransactionException
See Also

public void cleanupTransaction (Object transactionData)

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

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

public ConnectionHandle getJdbcConnection (PersistenceManager pm, boolean readOnly)

This implementation returns a DataStoreConnectionHandle for JDO2, which will also work on JDO1 until actually accessing the JDBC Connection.

For pre-JDO2 implementations, override this method to return the Connection through the corresponding vendor-specific mechanism, or null if the Connection is not retrievable.

NOTE: A JDO2 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 JDO2 DataStoreConnection is only "borrowed" from the PersistenceManager: it needs to be returned as early as possible. Effectively, JDO2 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).

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
JDOException
SQLException
See Also

public SQLExceptionTranslator getJdbcExceptionTranslator ()

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

public void releaseJdbcConnection (ConnectionHandle conHandle, PersistenceManager pm)

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.

Parameters
conHandle the JDBC Connection handle to release
pm the current JDO PersistenceManager
Throws
JDOException
SQLException
See Also

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

public DataAccessException translateException (JDOException ex)

This implementation delegates to PersistenceManagerFactoryUtils.

Parameters
ex the JDOException thrown
Returns
  • the corresponding DataAccessException (must not be null)
See Also

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.

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

Protected Methods

protected String extractSqlStringFromException (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