org.datanucleus.store.rdbms
Class RDBMSPersistenceHandler

java.lang.Object
  org.datanucleus.store.rdbms.RDBMSPersistenceHandler

All Implemented Interfaces:

org.datanucleus.store.StorePersistenceHandler

public class RDBMSPersistenceHandler
extends java.lang.Object
implements org.datanucleus.store.StorePersistenceHandler

Handler for persistence for RDBMS datastores. Makes use of the plugin-point "org.datanucleus.store.rdbms.rdbms_request" defining which request handlers we should use for the different operations.

Field Summary

protected static org.datanucleus.util.Localiser	LOCALISER Localiser for messages.
protected org.datanucleus.store.mapped.MappedStoreManager	storeMgr Manager for the store.

Constructor Summary

RDBMSPersistenceHandler(org.datanucleus.store.StoreManager storeMgr)
Constructor.

Method Summary

void	close() Method to close the handler and release any resources.
void	deleteObject(org.datanucleus.StateManager sm) Deletes a persistent object from the database.
void	fetchObject(org.datanucleus.StateManager sm, int[] fieldNumbers) Fetches a persistent object from the database.
java.lang.Object	findObject(org.datanucleus.ObjectManager om, java.lang.Object id) Method to return a persistable object with the specified id.
void	insertObject(org.datanucleus.StateManager sm) Inserts a persistent object into the database.
void	locateObject(org.datanucleus.StateManager sm) Locates this object in the datastore.
void	removeAllRequests() Convenience method to remove all requests since the schema has changed.
void	removeRequestsForTable(org.datanucleus.store.mapped.DatastoreClass table) Convenience method to remove all requests that use a particular table since the structure of the table has changed potentially leading to missing columns in the cached version.
void	updateObject(org.datanucleus.StateManager sm, int[] fieldNumbers) Updates a persistent object in the database.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOCALISER

protected static final org.datanucleus.util.Localiser LOCALISER

Localiser for messages.

storeMgr

protected final org.datanucleus.store.mapped.MappedStoreManager storeMgr

Manager for the store.

Constructor Detail

RDBMSPersistenceHandler

public RDBMSPersistenceHandler(org.datanucleus.store.StoreManager storeMgr)

Constructor.

Parameters:

storeMgr - StoreManager

Method Detail

close

public void close()

Method to close the handler and release any resources.

Specified by:

close in interface org.datanucleus.store.StorePersistenceHandler

insertObject

public void insertObject(org.datanucleus.StateManager sm)

Inserts a persistent object into the database.

Specified by:

insertObject in interface org.datanucleus.store.StorePersistenceHandler

Parameters:

sm - The state manager of the object to be inserted.

Throws:

org.datanucleus.exceptions.NucleusDataStoreException - when an error occurs in the datastore communication

fetchObject

public void fetchObject(org.datanucleus.StateManager sm,
                        int[] fieldNumbers)

Fetches a persistent object from the database.

Specified by:

fetchObject in interface org.datanucleus.store.StorePersistenceHandler

Parameters:

sm - The state manager of the object to be fetched.

fieldNumbers - The numbers of the fields to be fetched.

Throws:

org.datanucleus.exceptions.NucleusObjectNotFoundException - if the object doesnt exist

org.datanucleus.exceptions.NucleusDataStoreException - when an error occurs in the datastore communication

updateObject

public void updateObject(org.datanucleus.StateManager sm,
                         int[] fieldNumbers)

Updates a persistent object in the database.

Specified by:

updateObject in interface org.datanucleus.store.StorePersistenceHandler

Parameters:

sm - The state manager of the object to be updated.

fieldNumbers - The numbers of the fields to be updated.

Throws:

org.datanucleus.exceptions.NucleusDataStoreException - when an error occurs in the datastore communication

deleteObject

public void deleteObject(org.datanucleus.StateManager sm)

Deletes a persistent object from the database.

Specified by:

deleteObject in interface org.datanucleus.store.StorePersistenceHandler

Parameters:

sm - The state manager of the object to be deleted.

Throws:

org.datanucleus.exceptions.NucleusDataStoreException - when an error occurs in the datastore communication

locateObject

public void locateObject(org.datanucleus.StateManager sm)

Locates this object in the datastore.

Specified by:

locateObject in interface org.datanucleus.store.StorePersistenceHandler

Parameters:

sm - The StateManager for the object to be found

Throws:

org.datanucleus.exceptions.NucleusObjectNotFoundException - if the object doesnt exist

org.datanucleus.exceptions.NucleusDataStoreException - when an error occurs in the datastore communication

findObject

public java.lang.Object findObject(org.datanucleus.ObjectManager om,
                                   java.lang.Object id)

Method to return a persistable object with the specified id. Optional operation for StoreManagers. Should return a (at least) hollow PersistenceCapable object if the store manager supports the operation. If the StoreManager is managing the in-memory object instantiation (as part of co-managing the object lifecycle in general), then the StoreManager has to create the object during this call (if it is not already created). Most relational databases leave the in-memory object instantion to Core, but some object databases may manage the in-memory object instantion, effectively preventing Core of doing this.

StoreManager implementations may simply return null, indicating that they leave the object instantiate to us. Other implementations may instantiate the object in question (whether the implementation may trust that the object is not already instantiated has still to be determined). If an implementation believes that an object with the given ID should exist, but in fact does not exist, then the implementation should throw a RuntimeException. It should not silently return null in this case.

Specified by:

findObject in interface org.datanucleus.store.StorePersistenceHandler

Parameters:

om - the ObjectManager which will manage the object

id - the id of the object in question.

Returns:

a persistable object with a valid object state (for example: hollow) or null, indicating that the implementation leaves the instantiation work to us.

removeAllRequests

public void removeAllRequests()

Convenience method to remove all requests since the schema has changed.

removeRequestsForTable

public void removeRequestsForTable(org.datanucleus.store.mapped.DatastoreClass table)

Convenience method to remove all requests that use a particular table since the structure of the table has changed potentially leading to missing columns in the cached version.

Parameters:

table - The table