Spring Framework

org.springframework.orm.jdo
Class DefaultJdoDialect

java.lang.Object
  extended by org.springframework.orm.jdo.DefaultJdoDialect
All Implemented Interfaces:
PersistenceExceptionTranslator, JdoDialect

public class DefaultJdoDialect
extends java.lang.Object
implements JdoDialect, PersistenceExceptionTranslator

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.

Since:
1.1
Author:
Juergen Hoeller
See Also:
setJdbcExceptionTranslator(org.springframework.jdbc.support.SQLExceptionTranslator), JdoAccessor.setJdoDialect(org.springframework.orm.jdo.JdoDialect), JdoTransactionManager.setJdoDialect(org.springframework.orm.jdo.JdoDialect), PersistenceExceptionTranslationPostProcessor

Field Summary
protected  org.apache.commons.logging.Log logger
           
 
Constructor Summary
DefaultJdoDialect()
          Create a new DefaultJdoDialect.
DefaultJdoDialect(java.lang.Object connectionFactory)
          Create a new DefaultJdoDialect.
 
Method Summary
 void applyQueryTimeout(javax.jdo.Query query, int remainingTimeInSeconds)
          This implementation applies a JDO 3.0 query timeout, if available.
 java.lang.Object beginTransaction(javax.jdo.Transaction transaction, TransactionDefinition definition)
          This implementation invokes the standard JDO Transaction.begin method.
 void cleanupTransaction(java.lang.Object transactionData)
          This implementation does nothing, as the default beginTransaction implementation does not require any cleanup.
protected  java.lang.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 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, 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(java.lang.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
 

Field Detail

logger

protected final org.apache.commons.logging.Log logger
Constructor Detail

DefaultJdoDialect

public DefaultJdoDialect()
Create a new DefaultJdoDialect.


DefaultJdoDialect

public DefaultJdoDialect(java.lang.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 java.lang.Object beginTransaction(javax.jdo.Transaction transaction,
                                         TransactionDefinition definition)
                                  throws javax.jdo.JDOException,
                                         java.sql.SQLException,
                                         TransactionException
This implementation invokes the standard JDO Transaction.begin method. Throws an InvalidIsolationLevelException if a non-default isolation level is set.

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
java.sql.SQLException - if thrown by JDBC methods
TransactionException - in case of invalid arguments
See Also:
Transaction.begin(), InvalidIsolationLevelException

cleanupTransaction

public void cleanupTransaction(java.lang.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,
                                          java.sql.SQLException
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).

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
java.sql.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,
                                  java.sql.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
java.sql.SQLException - if thrown by JDBC methods
See Also:
Connection.close()

applyQueryTimeout

public void applyQueryTimeout(javax.jdo.Query query,
                              int remainingTimeInSeconds)
                       throws javax.jdo.JDOException
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.

Specified by:
applyQueryTimeout in interface JdoDialect
Parameters:
query - the JDO query object to apply the timeout to
remainingTimeInSeconds - the timeout value (seconds) to apply
Throws:
javax.jdo.JDOException - if thrown by JDO methods
See Also:
JdoTemplate.prepareQuery(javax.jdo.Query)

translateExceptionIfPossible

public DataAccessException translateExceptionIfPossible(java.lang.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 java.lang.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

Spring Framework