javax.jdo.spi
Interface StateInterrogation
public interface StateInterrogation
This interface is implemented by a non-binary-compatible JDO implementation
to provide state interrogation for non-enhanced persistent classes.
A call to JDOHelper to get the status of an instance is handled
internally if the parameter instance implements PersistenceCapable.
For non-binary-compatible implementations, there is no requirement
that persistent instances implement PersistenceCapable. Therefore,
if the parameter does not implement PersistenceCapable, JDOHelper
delegates to all registered instances of StateInterrogation until
an instance can handle the request.
For JDOHelper isXXX methods, which return boolean, the
corresponding method in StateInterrogation returns Boolean. If the
return value is
null
then the StateInterrogation does
not recognize the parameter as being handled by it. A non-null return
value indicates that the implementation has determined the answer.
For JDOHelper getXXX methods, which return an Object, each
registered StateInterrogation is given the parameter until one of
them returns a non-null value, which is passed to the caller.
For JDOHelper makeDirty, each
registered StateInterrogation is given the parameter until one of
them returns true, indicating that it has handled the call.
An instance that implements this interface must be registered with the
JDOImplHelper
.
Object | getObjectId(Object pc) - Return a copy of the JDO identity associated with the parameter
instance.
|
PersistenceManager | getPersistenceManager(Object pc) - Return the associated
PersistenceManager if there is one.
|
Object | getTransactionalObjectId(Object pc) - Return a copy of the JDO identity associated with the parameter
instance.
|
Object | getVersion(Object pc) - Return the version of the parameter instance.
|
Boolean | isDeleted(Object pc) - Tests whether the parameter instance has been deleted.
|
Boolean | isDetached(Object pc) - Tests whether the parameter instance is detached.
|
Boolean | isDirty(Object pc) - Tests whether the parameter instance is dirty.
|
Boolean | isNew(Object pc) - Tests whether the parameter instance has been newly made persistent.
|
Boolean | isPersistent(Object pc) - Tests whether the parameter instance is persistent.
|
Boolean | isTransactional(Object pc) - Tests whether the parameter instance is transactional.
|
boolean | makeDirty(Object pc, String fieldName) - Explicitly mark the parameter instance and field dirty.
|
getObjectId
public Object getObjectId(Object pc)
Return a copy of the JDO identity associated with the parameter
instance.
Persistent instances of
PersistenceCapable
classes
have a JDO identity
managed by the
PersistenceManager
. This method returns
a copy of the
ObjectId that represents the JDO identity.
Instances unknown by the implementation return
null
.
The ObjectId may be serialized
and later restored, and used with a
PersistenceManager
from the same JDO
implementation to locate a persistent instance with the same data store
identity.
If the JDO identity is managed by the application, then the ObjectId
may be used with a
PersistenceManager
from any JDO
implementation that supports
the
PersistenceCapable
class.
If the JDO identity is not managed by the application or the data
store, then the ObjectId returned is only valid within the current
transaction.
- a copy of the ObjectId of the parameter instance as of the
beginning of the transaction.
getPersistenceManager
public PersistenceManager getPersistenceManager(Object pc)
Return the associated
PersistenceManager
if there is one.
Transactional and persistent instances return the associated
PersistenceManager
.
Transient non-transactional instances return
null
.
Instances unknown by the implementation return
null
.
- the
PersistenceManager
associated with the
parameter instance.
getTransactionalObjectId
public Object getTransactionalObjectId(Object pc)
Return a copy of the JDO identity associated with the parameter
instance.
Instances unknown by the implementation return
null
.
- a copy of the ObjectId of the parameter instance as modified
in this transaction.
getVersion
public Object getVersion(Object pc)
Return the version of the parameter instance.
Instances unknown by the implementation return
null
.
- a copy of the ObjectId of the parameter instance as modified
in this transaction.
isDeleted
public Boolean isDeleted(Object pc)
Tests whether the parameter instance has been deleted.
Instances that have been deleted in the current transaction
return
Boolean.TRUE
.
Instances known by the implementation to be non-deleted
return
Boolean.FALSE
.
Instances not recognized by the implementation return
null
.
Boolean.TRUE
if the parameter instance was deleted
in the current transaction.
isDetached
public Boolean isDetached(Object pc)
Tests whether the parameter instance is detached.
Instances that are detached return
Boolean.TRUE
.
Instances known by the implementation to be non-detached
return
Boolean.FALSE
.
Instances not recognized by the implementation return
null
.
Boolean.TRUE
if the parameter instance is detached.
isDirty
public Boolean isDirty(Object pc)
Tests whether the parameter instance is dirty.
Instances that have been modified, deleted, newly
made persistent in the current transaction,
or modified while detached return
Boolean.TRUE
.
Instances known by the implementation to be non-dirty
return
Boolean.FALSE
.
Instances not recognized by the implementation return
null
.
Boolean.TRUE
if the parameter instance has been modified
in the current transaction, or while detached.
isNew
public Boolean isNew(Object pc)
Tests whether the parameter instance has been newly made persistent.
Instances that have been made persistent in the current transaction
return
Boolean.TRUE
.
Instances known by the implementation to be non-new
return
Boolean.FALSE
.
Instances not recognized by the implementation return
null
.
Boolean.TRUE
if the parameter instance was made persistent
in the current transaction.
isPersistent
public Boolean isPersistent(Object pc)
Tests whether the parameter instance is persistent.
Instances that represent persistent objects in the data store
return
Boolean.TRUE
.
Instances known by the implementation to be non-persistent
return
Boolean.FALSE
.
Instances not recognized by the implementation return
null
.
Boolean.TRUE
if the parameter instance is persistent.
isTransactional
public Boolean isTransactional(Object pc)
Tests whether the parameter instance is transactional.
Instances whose state is associated with the current transaction
return
Boolean.TRUE
.
Instances known by the implementation to be non-transactional
return
Boolean.FALSE
.
Instances not recognized by the implementation return
null
.
Boolean.TRUE
if the parameter instance is transactional.
makeDirty
public boolean makeDirty(Object pc,
String fieldName)
Explicitly mark the parameter instance and field dirty.
Normally,
PersistenceCapable
classes are able to detect
changes made
to their fields. However, if a reference to an array is given to a
method outside the class, and the array is modified, then the
persistent instance is not aware of the change. This API allows the
application to notify the instance that a change was made to a field.
Instances unknown by the implementation are unaffected.
pc
- the instance.fieldName
- the name of the field to be marked dirty.
PersistenceCapable.jdoMakeDirty(String fieldName)