ojb.broker
Class PersistenceBrokerImpl

java.lang.Object
  |
  +--ojb.broker.PersistenceBrokerImpl

All Implemented Interfaces:

PersistenceBroker

public class PersistenceBrokerImpl

extends java.lang.Object

implements PersistenceBroker

The PersistenceBrokerClient is an implementation of the PersistenceBroker Interface that specifies a persistence mechanism for generic objects. This Concrete implementation provides an object relational mapping and allows to store and retrieve arbitrary objects in/from relational databases accessed by JDBC.

Author:

Thomas Mahler

See Also:

for a sample application

Constructor Summary

PersistenceBrokerImpl(DescriptorRepository repository)

Method Summary

void	abortTransaction() Abort and close the transaction.
void	beginTransaction() begin a transaction against the underlying RDBMS.
void	checkPoint()
void	commitTransaction() Commit and close the transaction.
void	delete(java.lang.Object obj) deletes Object obj's representation in the underlying RDBMS
ManageableCollection	getCollectionByQuery(java.lang.Class collectionClass, Query query) retrieve a collection of itemClass Objects matching the Query query
java.util.Collection	getCollectionByQuery(Query query) retrieve a collection of itemClass Objects matching the Query query
ConnectionManager	getConnectionManager()
java.util.Iterator	getIteratorByQuery(Query query) returns an Iterator that iterates Objects of class c if calling the .next() method.
java.lang.Object	getObjectByIdentity(Identity id) Method declaration
java.lang.Object	getObjectByQuery(Query query) retrieve an Object by query I.e perform a SELECT ...
java.util.Enumeration	getPKEnumerationByQuery(java.lang.Class primaryKeyClass, Query query) returns an Enumeration of PrimaryKey Objects for objects of class DataClass.
StatementManager	getStatementManager()
int	getUniqueId(java.lang.Class extent, java.lang.String attribute) returns a unique int for class extent and field attribute. the returned uid is unique accross all tables in the extent of class extent.
boolean	isInTransaction() returns true if the broker is currently running a transaction.
void	removeFromCache(java.lang.Object obj) removes the objects obj from the brokers internal cache. removing is recursive.
void	retrieveCollections(java.lang.Object newObj, ClassDescriptor mif) Method declaration
void	retrieveReferences(java.lang.Object newObj, ClassDescriptor mif) Method declaration
static void	setDebug(boolean b) set the debugging flag to true to enable debugging
void	store(java.lang.Object obj) Method declaration
void	store(java.lang.Object obj, ObjectModification mod) makes object obj persistent in the underlying persistence system.
void	storeImmediate(java.lang.Object obj) make object obj persistent in the underlying persistence system. this method does not care about transactions.

Methods inherited from class java.lang.Object

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

Constructor Detail

PersistenceBrokerImpl

public PersistenceBrokerImpl(DescriptorRepository repository)

Method Detail

setDebug

public static void setDebug(boolean b)

set the debugging flag to true to enable debugging

getStatementManager

public StatementManager getStatementManager()

getConnectionManager

public ConnectionManager getConnectionManager()

delete

public void delete(java.lang.Object obj)
            throws PersistenceBrokerException

deletes Object obj's representation in the underlying RDBMS

Specified by:

delete in interface PersistenceBroker

store

public void store(java.lang.Object obj)
           throws PersistenceBrokerException

Method declaration

Specified by:

store in interface PersistenceBroker

Parameters:

obj -

Throws:

PersistenceBrokerException -

See Also:

retrieveReferences

public void retrieveReferences(java.lang.Object newObj,
                               ClassDescriptor mif)

Method declaration

Parameters:

newObj -

mif -

See Also:

retrieveCollections

public void retrieveCollections(java.lang.Object newObj,
                                ClassDescriptor mif)

Method declaration

Parameters:

newObj -

mif -

See Also:

abortTransaction

public void abortTransaction()
                      throws TransactionNotInProgressException

Abort and close the transaction. Calling abort abandons all persistent object modifications and releases the associated locks. If transaction is not in progress a TransactionNotInProgressException is thrown

Specified by:

abortTransaction in interface PersistenceBroker

beginTransaction

public void beginTransaction()
                      throws TransactionInProgressException,
                             TransactionAbortedException

begin a transaction against the underlying RDBMS. Calling beginTransaction multiple times, without an intervening call to commitTransaction or abortTransaction, causes the exception TransactionInProgressException to be thrown on the second and subsequent calls.

Specified by:

beginTransaction in interface PersistenceBroker

commitTransaction

public void commitTransaction()
                       throws TransactionNotInProgressException,
                              TransactionAbortedException

Commit and close the transaction. Calling commit commits to the database all UPDATE, INSERT and DELETE statements called within the transaction and releases any locks held by the transaction. If beginTransaction() has not been called before a TransactionNotInProgressException exception is thrown. If the transaction cannot be commited a TransactionAbortedException exception is thrown.

Specified by:

commitTransaction in interface PersistenceBroker

checkPoint

public void checkPoint()
                throws TransactionNotInProgressException,
                       TransactionAbortedException

getCollectionByQuery

public ManageableCollection getCollectionByQuery(java.lang.Class collectionClass,
                                                 Query query)
                                          throws PersistenceBrokerException

retrieve a collection of itemClass Objects matching the Query query

Specified by:

getCollectionByQuery in interface PersistenceBroker

getCollectionByQuery

public java.util.Collection getCollectionByQuery(Query query)
                                          throws PersistenceBrokerException

retrieve a collection of itemClass Objects matching the Query query

Specified by:

getCollectionByQuery in interface PersistenceBroker

getIteratorByQuery

public java.util.Iterator getIteratorByQuery(Query query)
                                      throws PersistenceBrokerException

returns an Iterator that iterates Objects of class c if calling the .next() method. The Elements returned come from a SELECT ... WHERE Statement that is defined by the Query query. If itemProxy is null, no proxies are used.

Specified by:

getIteratorByQuery in interface PersistenceBroker

getObjectByIdentity

public java.lang.Object getObjectByIdentity(Identity id)
                                     throws PersistenceBrokerException

Method declaration

Specified by:

getObjectByIdentity in interface PersistenceBroker

Parameters:

id -

Returns:

Throws:

PersistenceBrokerException -

See Also:

getObjectByQuery

public java.lang.Object getObjectByQuery(Query query)
                                  throws PersistenceBrokerException

retrieve an Object by query I.e perform a SELECT ... FROM ... WHERE ... in an RDBMS

Specified by:

getObjectByQuery in interface PersistenceBroker

getPKEnumerationByQuery

public java.util.Enumeration getPKEnumerationByQuery(java.lang.Class primaryKeyClass,
                                                     Query query)
                                              throws PersistenceBrokerException

returns an Enumeration of PrimaryKey Objects for objects of class DataClass. The Elements returned come from a SELECT ... WHERE Statement that is defined by the fields and their coresponding values of vecFields and vecValues. Useful for EJB Finder Methods...

Specified by:

getPKEnumerationByQuery in interface PersistenceBroker

Parameters:

PrimaryKeyClass - the pk class for the searched objects

query - the query

store

public void store(java.lang.Object obj,
                  ObjectModification mod)
           throws PersistenceBrokerException

makes object obj persistent in the underlying persistence system. E.G. by INSERT INTO ... or UPDATE ... in an RDBMS. The ModificationState parameter can be used to generate optimized SQL code. This functionality is typically called from transaction managers, that track which objects have to be stored. Thus this store method does not use update cascading to referenced objects.

Specified by:

store in interface PersistenceBroker

isInTransaction

public boolean isInTransaction()

returns true if the broker is currently running a transaction.

Returns:

boolean

getUniqueId

public int getUniqueId(java.lang.Class extent,
                       java.lang.String attribute)

Description copied from interface: PersistenceBroker

returns a unique int for class extent and field attribute. the returned uid is unique accross all tables in the extent of class extent.

Specified by:

getUniqueId in interface PersistenceBroker

removeFromCache

public void removeFromCache(java.lang.Object obj)
                     throws PersistenceBrokerException

removes the objects obj from the brokers internal cache. removing is recursive. That is referenced Objects are also removed from the cache, if the auto-retrieve flag is set for obj.getClass() in the metadata repository.

Specified by:

removeFromCache in interface PersistenceBroker

storeImmediate

public void storeImmediate(java.lang.Object obj)
                    throws PersistenceBrokerException

make object obj persistent in the underlying persistence system. this method does not care about transactions. It just performs an immediate update or insert.

Specified by:

storeImmediate in interface PersistenceBroker