/*
* Copyright 2002-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.orm.jdo;
import java.sql.SQLException;
import javax.jdo.JDOException;
import javax.jdo.PersistenceManager;
import javax.jdo.Query;
import javax.jdo.Transaction;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.datasource.ConnectionHandle;
import org.springframework.transaction.TransactionDefinition;
import org.springframework.transaction.TransactionException;
/**
* SPI strategy that allows for customizing integration with a specific JDO provider,
* in particular regarding transaction management and exception translation. To be
* implemented for specific JDO providers such as JPOX, Kodo, Lido, Versant Open Access.
*
* <p>JDO 2.0 defines standard ways for most of the functionality covered here.
* Hence, Spring's {@link DefaultJdoDialect} uses the corresponding JDO 2.0 methods
* by default, to be overridden in a vendor-specific fashion if necessary.
* Vendor-specific subclasses of {@link DefaultJdoDialect} are still required for special
* transaction semantics and more sophisticated exception translation (if needed).
*
* <p>In general, it is recommended to derive from {@link DefaultJdoDialect} instead
* of implementing this interface directly. This allows for inheriting common
* behavior (present and future) from {@link DefaultJdoDialect}, only overriding
* specific hooks to plug in concrete vendor-specific behavior.
*
* @author Juergen Hoeller
* @since 02.11.2003
* @see JdoTransactionManager#setJdoDialect
* @see JdoAccessor#setJdoDialect
* @see DefaultJdoDialect
*/
public interface JdoDialect {
//-------------------------------------------------------------------------
// Hooks for transaction management (used by JdoTransactionManager)
//-------------------------------------------------------------------------
/**
* Begin the given JDO transaction, applying the semantics specified by the
* given Spring transaction definition (in particular, an isolation level
* and a timeout). Invoked by JdoTransactionManager on transaction begin.
* <p>An implementation can configure the JDO Transaction object and then
* invoke <code>begin</code>, or invoke a special begin method that takes,
* for example, an isolation level.
* <p>An implementation can also apply read-only flag and isolation level to the
* underlying JDBC Connection before beginning the transaction. In that case,
* a transaction data object can be returned that holds the previous isolation
* level (and possibly other data), to be reset in <code>cleanupTransaction</code>.
* <p>Implementations can also use the Spring transaction name, as exposed by the
* passed-in TransactionDefinition, to optimize for specific data access use cases
* (effectively using the current transaction name as use case identifier).
* @param transaction the JDO transaction to begin
* @param definition the Spring transaction definition that defines semantics
* @return an arbitrary object that holds transaction data, if any
* (to be passed into cleanupTransaction)
* @throws JDOException if thrown by JDO methods
* @throws SQLException if thrown by JDBC methods
* @throws TransactionException in case of invalid arguments
* @see #cleanupTransaction
* @see javax.jdo.Transaction#begin
* @see org.springframework.jdbc.datasource.DataSourceUtils#prepareConnectionForTransaction
*/
Object beginTransaction(Transaction transaction, TransactionDefinition definition)
throws JDOException, SQLException, TransactionException;
/**
* Clean up the transaction via the given transaction data.
* Invoked by JdoTransactionManager on transaction cleanup.
* <p>An implementation can, for example, reset read-only flag and
* isolation level of the underlying JDBC Connection. Furthermore,
* an exposed data access use case can be reset here.
* @param transactionData arbitrary object that holds transaction data, if any
* (as returned by beginTransaction)
* @see #beginTransaction
* @see org.springframework.jdbc.datasource.DataSourceUtils#resetConnectionAfterTransaction
*/
void cleanupTransaction(Object transactionData);
/**
* Retrieve the JDBC Connection that the given JDO PersistenceManager uses underneath,
* if accessing a relational database. This method will just get invoked if actually
* needing access to the underlying JDBC Connection, usually within an active JDO
* transaction (for example, by JdoTransactionManager). The returned handle will
* be passed into the <code>releaseJdbcConnection</code> method when not needed anymore.
* <p>Implementations are encouraged to return an unwrapped Connection object, i.e.
* the Connection as they got it from the connection pool. This makes it easier for
* application code to get at the underlying native JDBC Connection, like an
* OracleConnection, which is sometimes necessary for LOB handling etc. We assume
* that calling code knows how to properly handle the returned Connection object.
* <p>In a simple case where the returned Connection will be auto-closed with the
* PersistenceManager or can be released via the Connection object itself, an
* implementation can return a SimpleConnectionHandle that just contains the
* Connection. If some other object is needed in <code>releaseJdbcConnection</code>,
* an implementation should use a special handle that references that other object.
* @param pm the current JDO PersistenceManager
* @param readOnly whether the Connection is only needed for read-only purposes
* @return a handle for the JDBC Connection, to be passed into
* <code>releaseJdbcConnection</code>, or <code>null</code>
* if no JDBC Connection can be retrieved
* @throws JDOException if thrown by JDO methods
* @throws SQLException if thrown by JDBC methods
* @see #releaseJdbcConnection
* @see org.springframework.jdbc.datasource.ConnectionHandle#getConnection
* @see org.springframework.jdbc.datasource.SimpleConnectionHandle
* @see JdoTransactionManager#setDataSource
* @see org.springframework.jdbc.support.nativejdbc.NativeJdbcExtractor
*/
ConnectionHandle getJdbcConnection(PersistenceManager pm, boolean readOnly)
throws JDOException, SQLException;
/**
* Release the given JDBC Connection, which has originally been retrieved
* via <code>getJdbcConnection</code>. This should be invoked in any case,
* to allow for proper release of the retrieved Connection handle.
* <p>An implementation might simply do nothing, if the Connection returned
* by <code>getJdbcConnection</code> will be implicitly closed when the JDO
* transaction completes or when the PersistenceManager is closed.
* @param conHandle the JDBC Connection handle to release
* @param pm the current JDO PersistenceManager
* @throws JDOException if thrown by JDO methods
* @throws SQLException if thrown by JDBC methods
* @see #getJdbcConnection
*/
void releaseJdbcConnection(ConnectionHandle conHandle, PersistenceManager pm)
throws JDOException, SQLException;
/**
* Flush the given PersistenceManager, i.e. flush all changes (that have been
* applied to persistent objects) to the underlying database. This method will
* just get invoked when eager flushing is actually necessary, for example when
* JDBC access code needs to see changes within the same transaction.
* @param pm the current JDO PersistenceManager
* @throws JDOException in case of errors
* @see JdoAccessor#setFlushEager
*/
void flush(PersistenceManager pm) throws JDOException;
/**
* Apply the given timeout to the given JDO query object.
* <p>Invoked with the remaining time of a specified transaction timeout, if any.
* @param query the JDO query object to apply the timeout to
* @param timeout the timeout value to apply
* @throws JDOException if thrown by JDO methods
* @see JdoTemplate#prepareQuery
*/
void applyQueryTimeout(Query query, int timeout) throws JDOException;
//-----------------------------------------------------------------------------------
// Hook for exception translation (used by JdoTransactionManager and JdoTemplate)
//-----------------------------------------------------------------------------------
/**
* Translate the given JDOException to a corresponding exception from Spring's
* generic DataAccessException hierarchy. An implementation should apply
* PersistenceManagerFactoryUtils' standard exception translation if can't do
* anything more specific.
* <p>Of particular importance is the correct translation to
* DataIntegrityViolationException, for example on constraint violation.
* Unfortunately, standard JDO does not allow for portable detection of this.
* <p>Can use a SQLExceptionTranslator for translating underlying SQLExceptions
* in a database-specific fashion.
* @param ex the JDOException thrown
* @return the corresponding DataAccessException (must not be <code>null</code>)
* @see JdoAccessor#convertJdoAccessException
* @see JdoTransactionManager#convertJdoAccessException
* @see PersistenceManagerFactoryUtils#convertJdoAccessException
* @see org.springframework.dao.DataIntegrityViolationException
* @see org.springframework.jdbc.support.SQLExceptionTranslator
*/
DataAccessException translateException(JDOException ex);
}