java.lang.Object
- org.springframework.orm.jdo.DefaultJdoDialect

All Implemented Interfaces:
PersistenceExceptionTranslator, JdoDialect
```
public class DefaultJdoDialect
extends Object
implements JdoDialect, PersistenceExceptionTranslator
```
Default implementation of the JdoDialect interface. As of Spring 4.0, designed for JDO 3.0 (or rather, semantics beyond JDO 3.0). Used as default dialect by JdoTransactionManager.
Simply begins a standard JDO transaction in beginTransaction. Returns a handle for a JDO DataStoreConnection on getJdbcConnection. Calls the corresponding JDO PersistenceManager operation on 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 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.
Since:
1.1
Author:
Juergen Hoeller
See Also:
setJdbcExceptionTranslator(org.springframework.jdbc.support.SQLExceptionTranslator), JdoTransactionManager.setJdoDialect(org.springframework.orm.jdo.JdoDialect), PersistenceExceptionTranslationPostProcessor

Constructor Summary
Constructors
Constructor Description
DefaultJdoDialect()
Create a new DefaultJdoDialect.
DefaultJdoDialect(Object connectionFactory)
Create a new DefaultJdoDialect.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Object`	`beginTransaction(javax.jdo.Transaction transaction, TransactionDefinition definition)`	This implementation invokes the standard JDO `Transaction.begin()` method and also `Transaction.setIsolationLevel(String)` if necessary.
`void`	`cleanupTransaction(Object transactionData)`	This implementation does nothing, as the default beginTransaction implementation does not require any cleanup.
`protected 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 JDO.
`SQLExceptionTranslator`	`getJdbcExceptionTranslator()`	Return the JDBC exception translator for this dialect, if any.
`protected String`	`getJdoIsolationLevel(TransactionDefinition definition)`	Determine the JDO isolation level String to use for the given Spring transaction definition.
`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(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

- Constructor Detail
  - DefaultJdoDialect
```
public DefaultJdoDialect()
```
    Create a new DefaultJdoDialect.
  - DefaultJdoDialect
```
public DefaultJdoDialect(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 Object beginTransaction(javax.jdo.Transaction transaction,
                               TransactionDefinition definition)
                        throws javax.jdo.JDOException,
                               SQLException,
                               TransactionException
```
    This implementation invokes the standard JDO Transaction.begin() method and also Transaction.setIsolationLevel(String) if necessary.
    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
    SQLException - if thrown by JDBC methods
    TransactionException - in case of invalid arguments
    See Also:
    Transaction.begin(), InvalidIsolationLevelException
  - getJdoIsolationLevel
```
protected String getJdoIsolationLevel(TransactionDefinition definition)
```
    Determine the JDO isolation level String to use for the given Spring transaction definition.
    Parameters:
    definition - the Spring transaction definition
    Returns:
    the corresponding JDO isolation level String, or null to indicate that no isolation level should be set explicitly
    See Also:
    Transaction.setIsolationLevel(String), Constants.TX_SERIALIZABLE, Constants.TX_REPEATABLE_READ, Constants.TX_READ_COMMITTED, Constants.TX_READ_UNCOMMITTED
  - cleanupTransaction
```
public void cleanupTransaction(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,
                                          SQLException
```
    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 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
    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,
                                  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
    SQLException - if thrown by JDBC methods
    See Also:
    Connection.close()
  - translateExceptionIfPossible
```
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.
    Specified by:
    translateExceptionIfPossible in interface PersistenceExceptionTranslator
    Parameters:
    ex - a RuntimeException to translate
    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 from 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 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

Constructor	Description
`DefaultJdoDialect()`	Create a new DefaultJdoDialect.
`DefaultJdoDialect(Object connectionFactory)`	Create a new DefaultJdoDialect.

Class DefaultJdoDialect

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DefaultJdoDialect

DefaultJdoDialect

Method Detail

setJdbcExceptionTranslator

getJdbcExceptionTranslator

beginTransaction

getJdoIsolationLevel

cleanupTransaction

getJdbcConnection

releaseJdbcConnection

translateExceptionIfPossible

translateException

extractSqlStringFromException