org.apache.ojb.broker.core
Class PersistenceBrokerImpl

java.lang.Object
  org.apache.ojb.broker.core.PersistenceBrokerAbstractImpl
      org.apache.ojb.broker.core.PersistenceBrokerImpl

All Implemented Interfaces:

org.apache.ojb.broker.util.configuration.Configurable, ObjectContainer, PBState, PersistenceBroker

public class PersistenceBrokerImpl

extends PersistenceBrokerAbstractImpl

implements PBState

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

Version:

$Id: PersistenceBrokerImpl.java,v 1.68 2004/02/17 20:52:30 baserose Exp $

Author:

Thomas Mahler, Leandro Rodrigo Saad Cruz, Matthew Baird, Jakob Braeuchi

See Also:

for a sample application

Constructor Summary

PersistenceBrokerImpl(PBKey key, PersistenceBrokerFactoryIF pbf)
Constructor used by PersistenceBrokerFactoryIF implementation.

Method Summary

void	abortTransaction() Abort and close the transaction.
void	addMtoNImplementor(MtoNImplementor m2n)
void	beginTransaction() begin a transaction against the underlying RDBMS.
void	clearCache() clears the brokers internal cache.
boolean	close() Close this PersistenceBroker so that no further requests may be made on it.
void	commitTransaction() Commit and close the transaction.
void	delete(java.lang.Object obj) deletes the objects obj concrete representation in the underlying persistence system.
void	deleteByQuery(Query query) Deletes all objects matching the query from the underlying persistence system.
void	deleteMtoNImplementor(MtoNImplementor m2nImpl) Deletes and MtoN implementor (a row on a indirection table) As it is today, ojb doesn't handle collection inherence, so collections descriptors are written per class.
void	destroy() Release all resources used by this class - CAUTION: No further operations can be done with this instance after calling this method.
java.lang.Object	doGetObjectByIdentity(Identity id) Internal used method to retrieve object based on Identity.
ClassDescriptor	getClassDescriptor(java.lang.Class clazz) returns a ClassDescriptor for the persistence capable class clazz.
ManageableCollection	getCollectionByQuery(java.lang.Class collectionClass, Query query) retrieve a collection of type collectionClass matching the Query query
java.util.Collection	getCollectionByQuery(Query query) retrieve a collection of itemClass Objects matching the Query query
int	getCount(Query query) Returns the count of elements a given query will return.
DescriptorRepository	getDescriptorRepository() Returns the DescriptorRepository associated with this broker.
org.apache.ojb.broker.cache.InternalCache	getInternalCache()
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) Retrieve an Object by its Identity.
java.lang.Object	getObjectByQuery(Query query) retrieve an Object by query I.e perform a SELECT ...
PBKey	getPBKey() Get the PBKey for this broker.
java.util.Enumeration	getPKEnumerationByQuery(java.lang.Class primaryKeyClass, Query query) returns an Enumeration of PrimaryKey Objects for objects of class DataClass.
QueryReferenceBroker	getReferenceBroker()
java.util.Iterator	getReportQueryIteratorByQuery(Query query) Get an Iterator based on the ReportQuery
java.lang.Class	getTopLevelClass(java.lang.Class clazz) Returns the top level (extent) class to which the given class belongs.
boolean	hasClassDescriptor(java.lang.Class clazz) same as getClassDescriptor, but does not throw.
boolean	isClosed()
boolean	isInTransaction() returns true if the broker is currently running a transaction.
Query	query() factory method to create a new Query object.
void	refresh() Lookup the current DescriptorRepository for this class.
void	refreshRelationships(java.lang.Object obj, ClassDescriptor cld) Refresh Relationships
void	removeFromCache(java.lang.Object obj) Removes the object from the brokers internal cache.
void	retrieveAllReferences(java.lang.Object pInstance) retrieve all References (also Collection-attributes) of a given instance.
void	retrieveReference(java.lang.Object pInstance, java.lang.String pAttributeName) retrieve a single reference- or collection attribute of a persistent instance.
org.apache.ojb.broker.util.BrokerHelper	serviceBrokerHelper() Returns the BrokerHelper instance associated with this broker.
org.apache.ojb.broker.accesslayer.ConnectionManagerIF	serviceConnectionManager() Returns the ConnectionManagerIF instance associated with this broker.
org.apache.ojb.broker.accesslayer.JdbcAccess	serviceJdbcAccess() Returns the JdbcAccess instance associated with this broker.
org.apache.ojb.broker.cache.ObjectCache	serviceObjectCache() Returns the ObjectCache instance associated with this broker.
SequenceManager	serviceSequenceManager() Returns the SequenceManager instance associated with this broker.
org.apache.ojb.broker.accesslayer.sql.SqlGenerator	serviceSqlGenerator() Returns the SqlGenerator instance associated with this broker.
org.apache.ojb.broker.accesslayer.StatementManagerIF	serviceStatementManager() Returns the StatementManagerIF instance associated with this broker.
void	setClosed(boolean closed)
void	setPBKey(PBKey key)
void	store(java.lang.Object obj) Store an Object
void	store(java.lang.Object obj, org.apache.ojb.broker.util.ObjectModification mod) makes object obj persistent in the underlying persistence system.

Methods inherited from class org.apache.ojb.broker.core.PersistenceBrokerAbstractImpl

addListener, addListener, configure, fireBrokerEvent, fireBrokerEvent, fireBrokerEvent, removeAllListeners, removeAllListeners, removeListener

Methods inherited from class java.lang.Object

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

Constructor Detail

PersistenceBrokerImpl

public PersistenceBrokerImpl(PBKey key,
                             PersistenceBrokerFactoryIF pbf)

Constructor used by PersistenceBrokerFactoryIF implementation.

Method Detail

getInternalCache

public org.apache.ojb.broker.cache.InternalCache getInternalCache()

serviceSqlGenerator

public org.apache.ojb.broker.accesslayer.sql.SqlGenerator serviceSqlGenerator()

Description copied from interface: PersistenceBroker

Returns the SqlGenerator instance associated with this broker.

Specified by:

serviceSqlGenerator in interface PersistenceBroker

serviceStatementManager

public org.apache.ojb.broker.accesslayer.StatementManagerIF serviceStatementManager()

Description copied from interface: PersistenceBroker

Returns the StatementManagerIF instance associated with this broker.

Specified by:

serviceStatementManager in interface PersistenceBroker

serviceJdbcAccess

public org.apache.ojb.broker.accesslayer.JdbcAccess serviceJdbcAccess()

Description copied from interface: PersistenceBroker

Returns the JdbcAccess instance associated with this broker.

Specified by:

serviceJdbcAccess in interface PersistenceBroker

serviceConnectionManager

public org.apache.ojb.broker.accesslayer.ConnectionManagerIF serviceConnectionManager()

Description copied from interface: PersistenceBroker

Returns the ConnectionManagerIF instance associated with this broker.

Specified by:

serviceConnectionManager in interface PersistenceBroker

serviceSequenceManager

public SequenceManager serviceSequenceManager()

Description copied from interface: PersistenceBroker

Returns the SequenceManager instance associated with this broker.

Specified by:

serviceSequenceManager in interface PersistenceBroker

serviceBrokerHelper

public org.apache.ojb.broker.util.BrokerHelper serviceBrokerHelper()

Description copied from interface: PersistenceBroker

Returns the BrokerHelper instance associated with this broker. Makes some helper methods available.

Specified by:

serviceBrokerHelper in interface PersistenceBroker

serviceObjectCache

public org.apache.ojb.broker.cache.ObjectCache serviceObjectCache()

Description copied from interface: PersistenceBroker

Returns the ObjectCache instance associated with this broker.

Specified by:

serviceObjectCache in interface PersistenceBroker

getReferenceBroker

public QueryReferenceBroker getReferenceBroker()

isClosed

public boolean isClosed()

Specified by:

isClosed in interface PersistenceBroker

setClosed

public void setClosed(boolean closed)

Specified by:

setClosed in interface PBState

refresh

public void refresh()

Lookup the current DescriptorRepository for this class. This method is responsible to keep this PB instance in sync with MetadataManager.

destroy

public void destroy()

Release all resources used by this class - CAUTION: No further operations can be done with this instance after calling this method.

getPBKey

public PBKey getPBKey()

Description copied from interface: PersistenceBroker

Get the PBKey for this broker.

Specified by:

getPBKey in interface PersistenceBroker

setPBKey

public void setPBKey(PBKey key)

close

public boolean close()

Description copied from interface: PersistenceBroker

Close this PersistenceBroker so that no further requests may be made on it. A PersistenceBroker instance can be used only until it is closed. Closing a PersistenceBroker might release it to the pool of available PersistenceBrokers, or might be garbage collected, at the option of the implementation.

Specified by:

close in interface PersistenceBroker

Returns:

true if successful

See Also:

PersistenceBroker.close()

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

Throws:

TransactionNotInProgressException

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

Throws:

TransactionInProgressException

TransactionAbortedException

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

Throws:

TransactionNotInProgressException

TransactionAbortedException

delete

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

Description copied from interface: PersistenceBroker

deletes the objects obj concrete representation in the underlying persistence system. E.G. by DELETE FROM ... WHERE ... in an RDBMS

Specified by:

delete in interface PersistenceBroker

Throws:

PersistenceBrokerException

See Also:

PersistenceBroker.delete(java.lang.Object)

deleteByQuery

public void deleteByQuery(Query query)
                   throws PersistenceBrokerException

Description copied from interface: PersistenceBroker

Deletes all objects matching the query from the underlying persistence system. E.G. by DELETE FROM ... WHERE ... in an RDBMS

Specified by:

deleteByQuery in interface PersistenceBroker

Throws:

PersistenceBrokerException

See Also:

PersistenceBroker.deleteByQuery(Query)

store

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

Store an Object

Specified by:

store in interface PersistenceBroker

Throws:

PersistenceBrokerException

See Also:

PersistenceBroker.store(Object)

retrieveAllReferences

public void retrieveAllReferences(java.lang.Object pInstance)
                           throws PersistenceBrokerException

retrieve all References (also Collection-attributes) of a given instance. Loading is forced, even if the collection- and reference-descriptors differ.

Specified by:

retrieveAllReferences in interface PersistenceBroker

Parameters:

pInstance - the persistent instance to work with

Throws:

PersistenceBrokerException

retrieveReference

public void retrieveReference(java.lang.Object pInstance,
                              java.lang.String pAttributeName)
                       throws PersistenceBrokerException

retrieve a single reference- or collection attribute of a persistent instance.

Specified by:

retrieveReference in interface PersistenceBroker

Parameters:

pInstance - the persistent instance

pAttributeName - the name of the Attribute to load

Throws:

PersistenceBrokerException

refreshRelationships

public void refreshRelationships(java.lang.Object obj,
                                 ClassDescriptor cld)

Refresh Relationships

Parameters:

obj -

cld -

Throws:

PersistenceBrokerException - if there is a error refreshing collections or references

getCollectionByQuery

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

retrieve a collection of type collectionClass matching the Query query

Specified by:

getCollectionByQuery in interface PersistenceBroker

Throws:

PersistenceBrokerException

See Also:

PersistenceBroker.getCollectionByQuery(Class, Query)

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

Throws:

PersistenceBrokerException

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

Throws:

PersistenceBrokerException

getObjectByIdentity

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

Description copied from interface: PersistenceBroker

Retrieve an Object by its Identity. Application Developers are encouraged to use getObjectByQuery(). This method is mainly used for internal performant handling of materialization by OID (e.g. in Proxies)

Specified by:

getObjectByIdentity in interface PersistenceBroker

Throws:

PersistenceBrokerException

doGetObjectByIdentity

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

Internal used method to retrieve object based on Identity.

Parameters:

id -

Returns:

Throws:

PersistenceBrokerException

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

Throws:

PersistenceBrokerException

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 listFields and listValues. Useful for EJB Finder Methods...

Specified by:

getPKEnumerationByQuery in interface PersistenceBroker

Parameters:

primaryKeyClass - the pk class for the searched objects

query - the query

Throws:

PersistenceBrokerException

store

public void store(java.lang.Object obj,
                  org.apache.ojb.broker.util.ObjectModification mod)
           throws PersistenceBrokerException

makes object obj persistent in the underlying persistence system. E.G. by INSERT INTO ... or UPDATE ... in an RDBMS. The ObjectModification parameter can be used to determine whether INSERT or update is to be used. This functionality is typically called from transaction managers, that track which objects have to be stored.

Specified by:

store in interface PersistenceBroker

Throws:

PersistenceBrokerException

isInTransaction

public boolean isInTransaction()

returns true if the broker is currently running a transaction.

Specified by:

isInTransaction in interface PersistenceBroker

Returns:

boolean

removeFromCache

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

Description copied from interface: PersistenceBroker

Removes the object from the brokers internal cache. If object is instance of Identity, the associated object was removed from cache.
Removing is not recursive.

Specified by:

removeFromCache in interface PersistenceBroker

Throws:

PersistenceBrokerException

See Also:

PersistenceBroker.removeFromCache(java.lang.Object)

getClassDescriptor

public ClassDescriptor getClassDescriptor(java.lang.Class clazz)
                                   throws PersistenceBrokerException

returns a ClassDescriptor for the persistence capable class clazz. throws a PersistenceBrokerException if clazz is not persistence capable, i.e. if clazz is not defined in the DescriptorRepository.

Specified by:

getClassDescriptor in interface PersistenceBroker

Throws:

PersistenceBrokerException

hasClassDescriptor

public boolean hasClassDescriptor(java.lang.Class clazz)

Description copied from interface: PersistenceBroker

same as getClassDescriptor, but does not throw. Useful for checking if an object is persistence Capable.

Specified by:

hasClassDescriptor in interface PersistenceBroker

Parameters:

clazz -

Returns:

true if descriptor was found

clearCache

public void clearCache()
                throws PersistenceBrokerException

clears 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:

clearCache in interface PersistenceBroker

Throws:

PersistenceBrokerException

getTopLevelClass

public java.lang.Class getTopLevelClass(java.lang.Class clazz)
                                 throws PersistenceBrokerException

Description copied from interface: PersistenceBroker

Returns the top level (extent) class to which the given class belongs. This may be a (abstract) base-class, an interface or the given class itself, if no extent is defined.

Specified by:

getTopLevelClass in interface PersistenceBroker

Throws:

PersistenceBrokerException - if clazz is not persistence capable, i.e. if clazz is not defined in the DescriptorRepository.

See Also:

PersistenceBroker.getTopLevelClass(java.lang.Class)

getCount

public int getCount(Query query)
             throws PersistenceBrokerException

Description copied from interface: PersistenceBroker

Returns the count of elements a given query will return.

Specified by:

getCount in interface PersistenceBroker

Throws:

PersistenceBrokerException

See Also:

PersistenceBroker.getCount(Query)

getReportQueryIteratorByQuery

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

Get an Iterator based on the ReportQuery

Specified by:

getReportQueryIteratorByQuery in interface PersistenceBroker

Parameters:

query -

Returns:

Iterator

Throws:

PersistenceBrokerException

query

public Query query()

Description copied from interface: ObjectContainer

factory method to create a new Query object.

Specified by:

query in interface ObjectContainer

Returns:

a new Query object

See Also:

ObjectContainer.query()

getDescriptorRepository

public DescriptorRepository getDescriptorRepository()

Description copied from interface: PersistenceBroker

Returns the DescriptorRepository associated with this broker.

Specified by:

getDescriptorRepository in interface PersistenceBroker

Returns:

DescriptorRepository

deleteMtoNImplementor

public void deleteMtoNImplementor(MtoNImplementor m2nImpl)
                           throws PersistenceBrokerException

Description copied from interface: PersistenceBroker

Deletes and MtoN implementor (a row on a indirection table) As it is today, ojb doesn't handle collection inherence, so collections descriptors are written per class. We try to match one of these collection descriptors, iterating from the left side and looking for possible for classes on the right side using : collection descriptor element . isAssinableFrom(rightClass) TODO: handle cache problems TODO: delete more than one row if possible Pre-coditions :

Pos-coditions :

Assertions :

Specified by:

deleteMtoNImplementor in interface PersistenceBroker

Parameters:

m2nImpl -

Throws:

PersistenceBrokerException - if an error occours

See Also:

PersistenceBroker.deleteMtoNImplementor(org.apache.ojb.broker.MtoNImplementor)

addMtoNImplementor

public void addMtoNImplementor(MtoNImplementor m2n)
                        throws PersistenceBrokerException

Specified by:

addMtoNImplementor in interface PersistenceBroker

Throws:

PersistenceBrokerException

See Also:

PersistenceBroker.addMtoNImplementor(org.apache.ojb.broker.MtoNImplementor)