public abstract class

JdoAccessor

extends Object
implements InitializingBean
java.lang.Object
   ↳ org.springframework.orm.jdo.JdoAccessor
Known Direct Subclasses

Class Overview

Base class for JdoTemplate and JdoInterceptor, defining common properties such as PersistenceManagerFactory and flushing behavior.

Note: With JDO, modifications to persistent objects are just possible within a transaction (in contrast to Hibernate). Therefore, eager flushing will just get applied when in a transaction. Furthermore, there is no explicit notion of flushing never, as this would not imply a performance gain due to JDO's field interception mechanism (which doesn't involve the overhead of snapshot comparisons).

Eager flushing is just available for specific JDO providers. You need to a corresponding JdoDialect to make eager flushing work.

Not intended to be used directly. See JdoTemplate and JdoInterceptor.

See Also

Summary

Fields
protected final Log logger Logger available to subclasses
Public Constructors
JdoAccessor()
Public Methods
void afterPropertiesSet()
Eagerly initialize the JDO dialect, creating a default one for the specified PersistenceManagerFactory if none set.
DataAccessException convertJdoAccessException(JDOException ex)
Convert the given JDOException to an appropriate exception from the org.springframework.dao hierarchy.
JdoDialect getJdoDialect()
Return the JDO dialect to use for this accessor.
PersistenceManagerFactory getPersistenceManagerFactory()
Return the JDO PersistenceManagerFactory that should be used to create PersistenceManagers.
boolean isFlushEager()
Return if this accessor should flush changes to the database eagerly.
void setFlushEager(boolean flushEager)
Set if this accessor should flush changes to the database eagerly.
void setJdoDialect(JdoDialect jdoDialect)
Set the JDO dialect to use for this accessor.
void setPersistenceManagerFactory(PersistenceManagerFactory pmf)
Set the JDO PersistenceManagerFactory that should be used to create PersistenceManagers.
Protected Methods
void flushIfNecessary(PersistenceManager pm, boolean existingTransaction)
Flush the given JDO persistence manager if necessary.
[Expand]
Inherited Methods
From class java.lang.Object
From interface org.springframework.beans.factory.InitializingBean

Fields

protected final Log logger

Logger available to subclasses

Public Constructors

public JdoAccessor ()

Public Methods

public void afterPropertiesSet ()

Eagerly initialize the JDO dialect, creating a default one for the specified PersistenceManagerFactory if none set.

public DataAccessException convertJdoAccessException (JDOException ex)

Convert the given JDOException to an appropriate exception from the org.springframework.dao hierarchy.

Default implementation delegates to the JdoDialect. May be overridden in subclasses.

Parameters
ex JDOException that occured
Returns
  • the corresponding DataAccessException instance
See Also

public JdoDialect getJdoDialect ()

Return the JDO dialect to use for this accessor.

Creates a default one for the specified PersistenceManagerFactory if none set.

public PersistenceManagerFactory getPersistenceManagerFactory ()

Return the JDO PersistenceManagerFactory that should be used to create PersistenceManagers.

public boolean isFlushEager ()

Return if this accessor should flush changes to the database eagerly.

public void setFlushEager (boolean flushEager)

Set if this accessor should flush changes to the database eagerly.

Eager flushing leads to immediate synchronization with the database, even if in a transaction. This causes inconsistencies to show up and throw a respective exception immediately, and JDBC access code that participates in the same transaction will see the changes as the database is already aware of them then. But the drawbacks are:

  • additional communication roundtrips with the database, instead of a single batch at transaction commit;
  • the fact that an actual database rollback is needed if the JDO transaction rolls back (due to already submitted SQL statements).

public void setJdoDialect (JdoDialect jdoDialect)

Set the JDO dialect to use for this accessor.

The dialect object can be used to retrieve the underlying JDBC connection and to eagerly flush changes to the database.

Default is a DefaultJdoDialect based on the PersistenceManagerFactory's underlying DataSource, if any.

public void setPersistenceManagerFactory (PersistenceManagerFactory pmf)

Set the JDO PersistenceManagerFactory that should be used to create PersistenceManagers.

Protected Methods

protected void flushIfNecessary (PersistenceManager pm, boolean existingTransaction)

Flush the given JDO persistence manager if necessary.

Parameters
pm the current JDO PersistenceManager
existingTransaction if executing within an existing transaction (within an existing JDO PersistenceManager that won't be closed immediately)
Throws
in case of JDO flushing errors
JDOException