Interface PersistenceManager
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- All Known Subinterfaces:
PersistenceManager
- All Known Implementing Classes:
PersistenceManagerImpl
,PersistenceManagerWrapper
public interface PersistenceManager
PersistenceManager is the primary interface for JDO-aware application components. It is the factory for Query and Transaction instances, and contains methods to manage the life cycle of PersistenceCapable instances.A PersistenceManager is obtained from the
PersistenceManagerFactory
(recommended) or by construction.- Version:
- 0.1
- Author:
- Craig Russell
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description void
close()
A PersistenceManager instance can be used until it is closed.Transaction
currentTransaction()
There is exactly one Transaction associated with a PersistenceManager.void
deletePersistent(Object pc)
Delete the persistent instance from the data store.void
deletePersistent(Object[] pcs)
Delete an array of instances from the data store.void
deletePersistent(Collection pcs)
Delete a Collection of instances from the data store.Collection
getExtent(Class persistenceCapableClass, boolean subclasses)
The PersistenceManager may manage a collection of instances in the data store based on the class of the instances.Object
getObjectById(Object oid)
This method locates a persistent instance in the cache of instances managed by this PersistenceManager.Object
getObjectById(Object oid, boolean validate)
This method locates a persistent instance in the cache of instances managed by thisPersistenceManager
.Object
getObjectId(Object pc)
The ObjectId returned by this method represents the JDO identity of the instance.Class
getObjectIdClass(Class cls)
In order for the application to construct instance of the ObjectId class it needs to know the class being used by the JDO implementation.PersistenceManagerFactory
getPersistenceManagerFactory()
This method returns the PersistenceManagerFactory used to create this PersistenceManager.Properties
getProperties()
The JDO vendor might store certain non-operational properties and make those properties available to applications (for troubleshooting).boolean
getRequireCopyObjectId()
Returns the boolean value of the requireCopyObjectId flag for this PersistenceManager.boolean
getRequireTrackedSCO()
Returns the boolean value of the requireTrackedSCO flag for this PersistenceManager.boolean
getSupersedeDeletedInstance()
Returns the boolean value of the supersedeDeletedInstance flag for this PersistenceManager.Object
getTransactionalInstance(Object pc)
This method is used to get a PersistenceCapable instance representing the same data store object as the parameter, that is valid for this PersistenceManager.Object
getUserObject()
The application can manage the PersistenceManager instances more easily by having an application object associated with each PersistenceManager instance.boolean
isClosed()
A PersistenceManager instance can be used until it is closed.void
makePersistent(Object pc)
Make the transient instance persistent in this PersistenceManager.void
makePersistent(Object[] pcs)
Make an array of instances persistent.void
makePersistent(Collection pcs)
Make a Collection of instances persistent.Object
newCollectionInstance(Class type, Object owner, String fieldName, Class elementType, boolean allowNulls, int initialSize)
Returns a new Collection instance of the type specified, with the owner and field name to notify upon changes to the value of any of its fields.Query
newQuery()
Create a new Query with no elements.Query
newQuery(Class cls)
Create a new Query specifying the Class of the candidate instances.Query
newQuery(Class cls, String filter)
Create a new Query with the Class of the candidate instances and Filter.Query
newQuery(Class cls, Collection cln)
Create a new Query with the Class of the candidate instances and candidate Collection.Query
newQuery(Class cls, Collection cln, String filter)
Create a new Query with the Class of the candidate instances, candidate Collection, and Filter.Query
newQuery(Object compiled)
Create a new Query using elements from another Query.Object
newSCOInstance(Class type, Object owner, String fieldName)
Returns a new Second Class Object instance of the type specified, with the owner and field name to notify upon changes to the value of any of its fields.void
setRequireCopyObjectId(boolean flag)
Sets the requireCopyObjectId flag for this PersistenceManager.void
setRequireTrackedSCO(boolean flag)
Sets the requireTrackedSCO flag for this PersistenceManager.void
setSupersedeDeletedInstance(boolean flag)
Sets the supersedeDeletedInstance flag for this PersistenceManager.void
setUserObject(Object o)
The application can manage the PersistenceManager instances more easily by having an application object associated with each PersistenceManager instance.
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Method Detail
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isClosed
boolean isClosed()
A PersistenceManager instance can be used until it is closed.- Returns:
- if this PersistenceManager has been closed
- See Also:
close()
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close
void close()
A PersistenceManager instance can be used until it is closed.This method closes the PersistenceManager, which if pooled, releases it to the pool of available PersistenceManagers.
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currentTransaction
Transaction currentTransaction()
There is exactly one Transaction associated with a PersistenceManager.- Returns:
- the Transaction associated with this PersistenceManager.
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newQuery
Query newQuery()
Create a new Query with no elements.- Returns:
- a new Query instance with no elements.
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newQuery
Query newQuery(Object compiled)
Create a new Query using elements from another Query. The other Query must have been created by the same JDO implementation. It might be active in a different PersistenceManager or might have been serialized and restored.- Parameters:
compiled
- another Query from the same JDO implementation- Returns:
- the new Query
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newQuery
Query newQuery(Class cls)
Create a new Query specifying the Class of the candidate instances.- Parameters:
cls
- the Class of the candidate instances- Returns:
- the new Query
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newQuery
Query newQuery(Class cls, Collection cln)
Create a new Query with the Class of the candidate instances and candidate Collection. specified.- Parameters:
cls
- the Class of the candidate instancescln
- the Collection of candidate instances- Returns:
- the new Query
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newQuery
Query newQuery(Class cls, String filter)
Create a new Query with the Class of the candidate instances and Filter. specified.- Parameters:
cls
- the Class of the candidate instancesfilter
- the Filter for candidate instances- Returns:
- the new Query
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newQuery
Query newQuery(Class cls, Collection cln, String filter)
Create a new Query with the Class of the candidate instances, candidate Collection, and Filter.- Parameters:
cls
- the Class of the candidate instancescln
- the Collection of candidate instancesfilter
- the Filter for candidate instances- Returns:
- the new Query
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getExtent
Collection getExtent(Class persistenceCapableClass, boolean subclasses)
The PersistenceManager may manage a collection of instances in the data store based on the class of the instances. This method returns a Collection of instances in the data store that might be iterated or given to a Query as the Collection of candidate instances.- Parameters:
persistenceCapableClass
- Class of instancessubclasses
- whether to include instances of subclasses- Returns:
- a Collection of instances
- See Also:
Query
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getObjectById
Object getObjectById(Object oid)
This method locates a persistent instance in the cache of instances managed by this PersistenceManager. If an instance with the same ObjectId is found it is returned. Otherwise, a new instance is created and associated with the ObjectId.If the instance does not exist in the data store, then this method will not fail. However, a request to access fields of the instance will throw an exception.
- Parameters:
oid
- an ObjectId- Returns:
- the PersistenceCapable instance with the specified ObjectId
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getObjectId
Object getObjectId(Object pc)
The ObjectId returned by this method represents the JDO identity of the instance. The ObjectId is a copy (clone) of the internal state of the instance, and changing it does not affect the JDO identity of the instance.- Parameters:
pc
- the PersistenceCapable instance- Returns:
- the ObjectId of the instance
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getTransactionalInstance
Object getTransactionalInstance(Object pc)
This method is used to get a PersistenceCapable instance representing the same data store object as the parameter, that is valid for this PersistenceManager.- Parameters:
pc
- a PersistenceCapable instance- Returns:
- the PersistenceCapable instance representing the same data store object
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makePersistent
void makePersistent(Object pc)
Make the transient instance persistent in this PersistenceManager. This method must be called in an active transaction. The PersistenceManager assigns an ObjectId to the instance and transitions it to persistent-new. The instance will be managed in the Extent associated with its Class. The instance will be put into the data store at commit.- Parameters:
pc
- a transient instance of a Class that implements PersistenceCapable
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makePersistent
void makePersistent(Object[] pcs)
Make an array of instances persistent.- Parameters:
pcs
- an array of transient instances- See Also:
makePersistent(Object pc)
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makePersistent
void makePersistent(Collection pcs)
Make a Collection of instances persistent.- Parameters:
pcs
- a Collection of transient instances- See Also:
makePersistent(Object pc)
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deletePersistent
void deletePersistent(Object pc)
Delete the persistent instance from the data store. This method must be called in an active transaction. The data store object will be removed at commit. Unlike makePersistent, which makes the closure of the instance persistent, the closure of the instance is not deleted from the data store. This method has no effect if the instance is already deleted in the current transaction. This method throws an exception if the instance is transient or is managed by another PersistenceManager.- Parameters:
pc
- a persistent instance
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deletePersistent
void deletePersistent(Object[] pcs)
Delete an array of instances from the data store.- Parameters:
pcs
- a Collection of persistent instances- See Also:
deletePersistent(Object pc)
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deletePersistent
void deletePersistent(Collection pcs)
Delete a Collection of instances from the data store.- Parameters:
pcs
- a Collection of persistent instances- See Also:
deletePersistent(Object pc)
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getPersistenceManagerFactory
PersistenceManagerFactory getPersistenceManagerFactory()
This method returns the PersistenceManagerFactory used to create this PersistenceManager. It returns null if this instance was created via a constructor.- Returns:
- the PersistenceManagerFactory that created this PersistenceManager
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setUserObject
void setUserObject(Object o)
The application can manage the PersistenceManager instances more easily by having an application object associated with each PersistenceManager instance.- Parameters:
o
- the user instance to be remembered by the PersistenceManager- See Also:
getUserObject()
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getUserObject
Object getUserObject()
The application can manage the PersistenceManager instances more easily by having an application object associated with each PersistenceManager instance.- Returns:
- the user object associated with this PersistenceManager
- See Also:
setUserObject(java.lang.Object)
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getProperties
Properties getProperties()
The JDO vendor might store certain non-operational properties and make those properties available to applications (for troubleshooting).Standard properties include:
- VendorName
- VersionNumber
- Returns:
- the Properties of this PersistenceManager
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getObjectIdClass
Class getObjectIdClass(Class cls)
In order for the application to construct instance of the ObjectId class it needs to know the class being used by the JDO implementation.- Parameters:
cls
- the PersistenceCapable Class- Returns:
- the Class of the ObjectId of the parameter
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newSCOInstance
Object newSCOInstance(Class type, Object owner, String fieldName)
Returns a new Second Class Object instance of the type specified, with the owner and field name to notify upon changes to the value of any of its fields. If a collection class is created, then the class does not restrict the element types, and allows nulls to be added as elements.- Parameters:
type
- Class of the new SCO instanceowner
- the owner to notify upon changesfieldName
- the field to notify upon changes- Returns:
- the object of the class type
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newCollectionInstance
Object newCollectionInstance(Class type, Object owner, String fieldName, Class elementType, boolean allowNulls, int initialSize)
Returns a new Collection instance of the type specified, with the owner and field name to notify upon changes to the value of any of its fields. The collection class restricts the element types allowed to the elementType or instances assignable to the elementType, and allows nulls to be added as elements based on the setting of allowNulls. The Collection has an initial size as specified by the initialSize parameter.- Parameters:
type
- Class of the new SCO instanceowner
- the owner to notify upon changesfieldName
- the field to notify upon changeselementType
- the element types allowedallowNulls
- true if allowedinitialSize
- initial size of the Collection- Returns:
- the object of the class type
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getObjectById
Object getObjectById(Object oid, boolean validate)
This method locates a persistent instance in the cache of instances managed by thisPersistenceManager
. ThegetObjectById
method attempts to find an instance in the cache with the specified JDO identity. Theoid
parameter object might have been returned by an earlier call togetObjectId
or might have been constructed by the application.If the
PersistenceManager
is unable to resolve theoid
parameter to an ObjectId instance, then it throws aJDOUserException
.If the
validate
flag isfalse
, and there is already an instance in the cache with the same JDO identity as theoid
parameter, then this method returns it. There is no change made to the state of the returned instance.If there is not an instance already in the cache with the same JDO identity as the
oid
parameter, then this method creates an instance with the specified JDO identity and returns it. If there is no transaction in progress, the returned instance will be hollow or persistent-nontransactional, at the choice of the implementation.If there is a transaction in progress, the returned instance will be hollow, persistent-nontransactional, or persistent-clean, at the choice of the implementation.
It is an implementation decision whether to access the data store, if required to determine the exact class. This will be the case of inheritance, where multiple
PersistenceCapable
classes share the same ObjectId class.If the validate flag is
false
, and the instance does not exist in the data store, then this method might not fail. It is an implementation choice whether to fail immediately with aJDODataStoreException
. But a subsequent access of the fields of the instance will throw aJDODataStoreException
if the instance does not exist at that time. Further, if a relationship is established to this instance, then the transaction in which the association was made will fail.If the
validate
flag istrue
, and there is already a transactional instance in the cache with the same JDO identity as theoid
parameter, then this method returns it. There is no change made to the state of the returned instance.If there is an instance already in the cache with the same JDO identity as the
oid
parameter, but the instance is not transactional, then it must be verified in the data store. If the instance does not exist in the datastore, then aJDODataStoreException
is thrown.If there is not an instance already in the cache with the same JDO identity as the
oid
parameter, then this method creates an instance with the specified JDO identity, verifies that it exists in the data store, and returns it. If there is no transaction in progress, the returned instance will be hollow or persistent-nontransactional, at the choice of the implementation.If there is a data store transaction in progress, the returned instance will be persistent-clean. If there is an optimistic transaction in progress, the returned instance will be persistent-nontransactional.
- Parameters:
oid
- an ObjectIdvalidate
- if the existence of the instance is to be validated- Returns:
- the
PersistenceCapable
instance with the specified ObjectId - See Also:
getObjectId(Object pc)
,getObjectById(Object oid)
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getSupersedeDeletedInstance
boolean getSupersedeDeletedInstance()
Returns the boolean value of the supersedeDeletedInstance flag for this PersistenceManager. If set to true, deleted instances are allowed to be replaced with persistent-new instances with the equal Object Id.- Returns:
- boolean supersedeDeletedInstance flag
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setSupersedeDeletedInstance
void setSupersedeDeletedInstance(boolean flag)
Sets the supersedeDeletedInstance flag for this PersistenceManager.- Parameters:
flag
- boolean supersedeDeletedInstance flag
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getRequireCopyObjectId
boolean getRequireCopyObjectId()
Returns the boolean value of the requireCopyObjectId flag for this PersistenceManager. If set to false, the PersistenceManager does not create a copy of an ObjectId forPersistenceManager.getObjectId(Object pc)
andPersistenceManager.getObjectById(Object oid)
requests.- Returns:
- boolean requireCopyObjectId flag
- See Also:
getObjectId(Object pc)
,getObjectById(Object oid)
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setRequireCopyObjectId
void setRequireCopyObjectId(boolean flag)
Sets the requireCopyObjectId flag for this PersistenceManager. If set to false, the PersistenceManager will not create a copy of an ObjectId forPersistenceManager.getObjectId(Object pc)
andPersistenceManager.getObjectById(Object oid)
requests.- Parameters:
flag
- boolean requireCopyObjectId flag- See Also:
getObjectId(Object pc)
,getObjectById(Object oid)
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getRequireTrackedSCO
boolean getRequireTrackedSCO()
Returns the boolean value of the requireTrackedSCO flag for this PersistenceManager. If set to false, the PersistenceManager will not create tracked SCO instances for new persistent instances at commit with retainValues set to true and while retrieving data from a datastore.- Returns:
- boolean requireTrackedSCO flag
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setRequireTrackedSCO
void setRequireTrackedSCO(boolean flag)
Sets the requireTrackedSCO flag for this PersistenceManager. If set to false, the PersistenceManager will not create tracked SCO instances for new persistent instances at commit with retainValues set to true and while retrieving data from a datastore.- Parameters:
flag
- boolean requireTrackedSCO flag
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