org.apache.causeway.persistence.jdo.spring.integration.DefaultJdoDialect Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
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*
* 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
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.causeway.persistence.jdo.spring.integration;
import java.sql.Connection;
import java.sql.SQLException;
import javax.jdo.Constants;
import javax.jdo.JDOException;
import javax.jdo.PersistenceManager;
import javax.jdo.Transaction;
import org.springframework.dao.DataAccessException;
import org.springframework.dao.support.PersistenceExceptionTranslator;
import org.springframework.jdbc.datasource.ConnectionHandle;
import org.springframework.jdbc.support.JdbcUtils;
import org.springframework.jdbc.support.SQLExceptionTranslator;
import org.springframework.transaction.TransactionDefinition;
import org.springframework.transaction.TransactionException;
/**
* Default implementation of the {@link JdoDialect} interface.
* As of Spring 4.0, designed for JDO 3.0 (or rather, semantics beyond JDO 3.0).
* Used as default dialect by {@link JdoTransactionManager}.
*
* Simply begins a standard JDO transaction in {@code beginTransaction}.
* Returns a handle for a JDO DataStoreConnection on {@code getJdbcConnection}.
* Calls the corresponding JDO PersistenceManager operation on {@code 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 {@code 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.
*
* @see #setJdbcExceptionTranslator
* @see JdoTransactionManager#setJdoDialect
* @see org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor
*/
public class DefaultJdoDialect implements JdoDialect, PersistenceExceptionTranslator {
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)
*/
public 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 {@link Transaction#begin()}
* method and also {@link Transaction#setIsolationLevel(String)} if necessary.
* @see javax.jdo.Transaction#begin
* @see org.springframework.transaction.InvalidIsolationLevelException
*/
@Override
public Object beginTransaction(Transaction transaction, TransactionDefinition definition)
throws JDOException, SQLException, TransactionException {
String jdoIsolationLevel = getJdoIsolationLevel(definition);
if (jdoIsolationLevel != null) {
transaction.setIsolationLevel(jdoIsolationLevel);
}
transaction.begin();
return null;
}
/**
* Determine the JDO isolation level String to use for the given
* Spring transaction definition.
* @param definition the Spring transaction definition
* @return the corresponding JDO isolation level String, or {@code null}
* to indicate that no isolation level should be set explicitly
* @see Transaction#setIsolationLevel(String)
* @see Constants#TX_SERIALIZABLE
* @see Constants#TX_REPEATABLE_READ
* @see Constants#TX_READ_COMMITTED
* @see Constants#TX_READ_UNCOMMITTED
*/
protected String getJdoIsolationLevel(TransactionDefinition definition) {
switch (definition.getIsolationLevel()) {
case TransactionDefinition.ISOLATION_SERIALIZABLE:
return Constants.TX_SERIALIZABLE;
case TransactionDefinition.ISOLATION_REPEATABLE_READ:
return Constants.TX_REPEATABLE_READ;
case TransactionDefinition.ISOLATION_READ_COMMITTED:
return Constants.TX_READ_COMMITTED;
case TransactionDefinition.ISOLATION_READ_UNCOMMITTED:
return Constants.TX_READ_UNCOMMITTED;
default:
return null;
}
}
/**
* This implementation does nothing, as the default beginTransaction implementation
* does not require any cleanup.
* @see #beginTransaction
*/
@Override
public void cleanupTransaction(Object transactionData) {
}
/**
* 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
* {@code DataSourceUtils.releaseConnection}).
* @see javax.jdo.PersistenceManager#getDataStoreConnection()
* @see org.springframework.jdbc.support.nativejdbc.NativeJdbcExtractor
* @see org.springframework.jdbc.datasource.DataSourceUtils#releaseConnection
*/
@Override
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
* {@code Connection.close} here.
* @see java.sql.Connection#close()
*/
@Override
public void releaseJdbcConnection(ConnectionHandle conHandle, PersistenceManager pm)
throws JDOException, SQLException {
}
//-----------------------------------------------------------------------------------
// Hook for exception translation (used by JdoTransactionManager)
//-----------------------------------------------------------------------------------
/**
* Implementation of the PersistenceExceptionTranslator interface,
* as autodetected by Spring's PersistenceExceptionTranslationPostProcessor.
*
Converts the exception if it is a JDOException, using this JdoDialect.
* Else returns {@code null} to indicate an unknown exception.
* @see org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor
* @see #translateException
*/
@Override
public DataAccessException translateExceptionIfPossible(RuntimeException ex) {
if (ex instanceof JDOException) {
return translateException((JDOException) ex);
}
return null;
}
/**
* This implementation delegates to PersistenceManagerFactoryUtils.
* @see PersistenceManagerFactoryUtils#convertJdoAccessException
*/
@Override
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 {@code 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 {@code null} if none found
*/
protected String extractSqlStringFromException(JDOException ex) {
return null;
}
/**
* ConnectionHandle implementation that fetches a new JDO DataStoreConnection
* for every {@code getConnection} call and closes the Connection on
* {@code releaseConnection}. This is necessary because JDO 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;
}
@Override
public Connection getConnection() {
return (Connection) this.persistenceManager.getDataStoreConnection();
}
@Override
public void releaseConnection(Connection con) {
JdbcUtils.closeConnection(con);
}
}
}