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. * * @author Juergen Hoeller * @since 1.1 * @see #setJdbcExceptionTranslator * @see JdoAccessor#setJdoDialect * @see JdoTransactionManager#setJdoDialect * @see org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor */ public class DefaultJdoDialect implements JdoDialect, PersistenceExceptionTranslator { protected final Log logger = LogFactory.getLog(getClass()); private SQLExceptionTranslator jdbcExceptionTranslator; /** * Create a new DefaultJdoDialect. */ public DefaultJdoDialect() { } /** * Create a new DefaultJdoDialect. * @param connectionFactory the connection factory of the JDO PersistenceManagerFactory, * which is used to initialize the default JDBC exception translator * @see javax.jdo.PersistenceManagerFactory#getConnectionFactory() * @see PersistenceManagerFactoryUtils#newJdbcExceptionTranslator(Object) */ DefaultJdoDialect(Object connectionFactory) { this.jdbcExceptionTranslator = PersistenceManagerFactoryUtils.newJdbcExceptionTranslator(connectionFactory); } /** * 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.
* @param jdbcExceptionTranslator exception translator
* @see java.sql.SQLException
* @see javax.jdo.JDOException#getCause()
* @see org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator
* @see org.springframework.jdbc.support.SQLStateSQLExceptionTranslator
*/
public void setJdbcExceptionTranslator(SQLExceptionTranslator jdbcExceptionTranslator) {
this.jdbcExceptionTranslator = jdbcExceptionTranslator;
}
/**
* Return the JDBC exception translator for this dialect, if any.
*/
public SQLExceptionTranslator getJdbcExceptionTranslator() {
return this.jdbcExceptionTranslator;
}
//-------------------------------------------------------------------------
// Hooks for transaction management (used by JdoTransactionManager)
//-------------------------------------------------------------------------
/**
* This implementation invokes the standard JDO Transaction.begin
* method. Throws an InvalidIsolationLevelException if a non-default isolation
* level is set.
* @see javax.jdo.Transaction#begin
* @see org.springframework.transaction.InvalidIsolationLevelException
*/
public Object beginTransaction(Transaction transaction, TransactionDefinition definition)
throws JDOException, SQLException, TransactionException {
if (definition.getIsolationLevel() != TransactionDefinition.ISOLATION_DEFAULT) {
throw new InvalidIsolationLevelException(
"Standard JDO does not support custom isolation levels: " +
"use a special JdoDialect implementation for your JDO provider");
}
transaction.begin();
return null;
}
/**
* This implementation does nothing, as the default beginTransaction implementation
* does not require any cleanup.
* @see #beginTransaction
*/
public void cleanupTransaction(Object transactionData) {
}
/**
* 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).
* @see javax.jdo.PersistenceManager#getDataStoreConnection()
* @see org.springframework.jdbc.support.nativejdbc.NativeJdbcExtractor
* @see org.springframework.jdbc.datasource.DataSourceUtils#releaseConnection
*/
public ConnectionHandle getJdbcConnection(PersistenceManager pm, boolean readOnly)
throws JDOException, SQLException {
return new DataStoreConnectionHandle(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.
* @see java.sql.Connection#close()
*/
public void releaseJdbcConnection(ConnectionHandle conHandle, PersistenceManager pm)
throws JDOException, SQLException {
}
/**
* This implementation delegates to JDO 2.0's flush method.
*
To be overridden for pre-JDO2 implementations, using the corresponding * vendor-specific mechanism there. * @see javax.jdo.PersistenceManager#flush() */ public void flush(PersistenceManager pm) throws JDOException { pm.flush(); } /** * This implementation logs a warning that it cannot apply a query timeout. */ public void applyQueryTimeout(Query query, int remainingTimeInSeconds) throws JDOException { logger.info("DefaultJdoDialect does not support query timeouts: ignoring remaining transaction time"); } //----------------------------------------------------------------------------------- // Hook for exception translation (used by JdoTransactionManager and JdoTemplate) //----------------------------------------------------------------------------------- /** * 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.
* @see org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor
* @see #translateException
*/
public DataAccessException translateExceptionIfPossible(RuntimeException ex) {
if (ex instanceof JDOException) {
return translateException((JDOException) ex);
}
return null;
}
/**
* This implementation delegates to PersistenceManagerFactoryUtils.
* @see PersistenceManagerFactoryUtils#convertJdoAccessException
*/
public DataAccessException translateException(JDOException ex) {
if (getJdbcExceptionTranslator() != null && ex.getCause() instanceof SQLException) {
return getJdbcExceptionTranslator().translate("JDO operation: " + ex.getMessage(),
extractSqlStringFromException(ex), (SQLException) ex.getCause());
}
return PersistenceManagerFactoryUtils.convertJdoAccessException(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.
* @param ex the JDOException, containing a SQLException
* @return the SQL String, or null if none found
*/
protected String extractSqlStringFromException(JDOException ex) {
return null;
}
/**
* ConnectionHandle implementation that fetches a new JDO2 DataStoreConnection
* for every getConnection call and closes the Connection on
* releaseConnection. This is necessary because JDO2 requires the
* fetched Connection to be closed before continuing PersistenceManager work.
* @see javax.jdo.PersistenceManager#getDataStoreConnection()
*/
private static class DataStoreConnectionHandle implements ConnectionHandle {
private final PersistenceManager persistenceManager;
public DataStoreConnectionHandle(PersistenceManager persistenceManager) {
this.persistenceManager = persistenceManager;
}
public Connection getConnection() {
return (Connection) this.persistenceManager.getDataStoreConnection();
}
public void releaseConnection(Connection con) {
JdbcUtils.closeConnection(con);
}
}
}