ClassMolder is a binder for one type of data object and its
Persistence
. For example, when ClassMolder is asked to load
an object, it acquires values from
Persistence
and binds it
into an target object. It also resolves relations via
TransactionContext
and bind related object into an target object.
Beside loading, ClassMolder is also repsonsible for storing, removing,
creating an object to and from a persistence storage, as well as
reverting an object to previous state.
Each instance of ClassMolder deals with exactly one persistable type,
interacts with one instance of Persistent and belongs to one
LockEngine
.
addDependent
(package private) void addDependent(ClassMolder dep)
Mutator method to add a dependent ClassMolder
addExtendent
(package private) void addExtendent(ClassMolder ext)
Mutator method to add a extent ClassMolder
create
public Object create(TransactionContext tx,
OID oid,
DepositBox locker,
Object object)
throws DuplicateIdentityException,
PersistenceException
Create an object of the base class with specified identity into the persistence storage.
tx
- transaction in actionoid
- the object identity of the object to be created.locker
- the dirty checking cache of the objectobject
- the object to be created
- the identity of the object
delete
public void delete(TransactionContext tx,
OID oid)
throws PersistenceException
Delete an object of the base type from the persistence storage.
All object to be deleted by this method will be markDelete
before it method is called.
tx
- - transaction in actionoid
- - the object identity of the target object
getAccessMode
public AccessMode getAccessMode(AccessMode txMode)
Get the effective accessMode of the the base type
txMode
- - the default transaction accessMode
- the effective acessMode of the base type
getActualIdentity
public Object getActualIdentity(ClassLoader loader,
Object o)
Get the identity from a object of the base type
loader
- the current class loadero
- - object of the base type
- return an Object[] which contains the identity of the object
getActualIdentity
public Object getActualIdentity(TransactionContext tx,
Object o)
Get the identity from a object of the base type
tx
- the transaction contexto
- - object of the base type
- return an Object[] which contains the identity of the object
getCacheParam
public int getCacheParam()
Return the preferred LRU cache capacity for caching object of this type
getCacheType
public int getCacheType()
Return the preferred LRU cache mechanism for caching object of this type
getCallback
public CallbackInterceptor getCallback()
Get the callback interceptor of the base type
getDepends
public ClassMolder getDepends()
Get the depends class' ClassMolder
getExtends
public ClassMolder getExtends()
Get the extends class' ClassMolder
getFields
public FieldMolder[] getFields()
Get the FieldMolder of the fields of the base type,
except the identity fields.
getIdentity
public Object getIdentity(TransactionContext tx,
Object o)
Get the identity from a object of the base type
If object isn't persistent and key generator is used, returns null
tx
- the transaction contexto
- - object of the base type
- return an Object[] which contains the identity of the object
getIds
public FieldMolder[] getIds()
Get the FieldMolders of the identity fields
getJavaClass
public Class getJavaClass(ClassLoader loader)
Get the base class of this ClassMolder given a ClassLoader
getLockEngine
public LockEngine getLockEngine()
Get the LockEngine which this ClassMolder belongs to.
getName
public String getName()
Get the fully qualified name of the base type of this ClassMolder
getPersistence
public Persistence getPersistence()
Get the Persisetence of the base type
getPriority
public int getPriority()
Determines the create priority of the data object class represented by
this ClassMolder. Concpetually, this method determines the order of
which data object should be created. Priority of zero means the object
can be created without depending on other data object.
This method should only be called after DatingService is closed.
isAssignableFrom
public boolean isAssignableFrom(Class cls)
check if the current ClassModlder is assignable from the class
instance.
cls
- the Class to check the assignation
isDefaultIdentity
public boolean isDefaultIdentity(Object identity)
Test if the specified identity is the default value of the type.
isDependent
public boolean isDependent()
Return true if the base type of this ClassMolder is an dependent
class.
isKeyGeneratorUsed
public boolean isKeyGeneratorUsed()
Return true if a key generator is used for the base type of this ClassMolder
load
public Object load(TransactionContext tx,
OID oid,
DepositBox locker,
Object object,
AccessMode suggestedAccessMode)
throws ObjectNotFoundException,
PersistenceException
Load an object with specified identity from the persistent storage.
tx
- the TransactionContext in actionoid
- the object identity of the desired objectlocker
- the DepositBox
of the object which is used to
store the dirty checking cache of the object.
- the object stamp for the object in the persistent storage
markDelete
public void markDelete(TransactionContext tx,
OID oid,
DepositBox locker,
Object object)
throws ObjectNotFoundException,
PersistenceException
Prepare to delete an object with the specified identity. If any sub-object
should be deleted along with the target object, it should be deleted
by this method.
tx
- - transaction in actionoid
- - object's identity of the target objectlocker
- - the dirty checking cache of the target objectobject
- - the target object
newInstance
public Object newInstance(ClassLoader loader)
Return a new instance of the base class with the provided ClassLoader object
- Object the object reprenseted by this ClassMolder, and instanciated
with the provided ClassLoader instance.
preStore
public boolean preStore(TransactionContext tx,
OID oid,
DepositBox locker,
Object object,
int timeout)
throws PersistenceException
Check the object for modification. If dpendent object is dereferenced, it
method will remove the object thru the transaction. If an related object
is dereferenced, it method will make sure the formally object will be
dereferenced from the other side as well.
This method is called in prepare (for commit) state of the transaction.
This method indicates if the object needed to be persist or cache should
be update using TransactionContext.markDelete.
tx
- transaction in actionoid
- the object identity of the objectlocker
- the dirty check cache for the objectobject
- the data object to be checkedtimeout
- timeout of updating the lock if needed
- true if the object is modified
resolve
public static Vector resolve(MappingLoader loader,
LockEngine lock,
PersistenceFactory factory,
LogInterceptor logInterceptor)
throws MappingException,
ClassNotFoundException
Resolve and construct all the ClassMolders given a MappingLoader.
loader
- MappingLoader for the LockEnginelock
- LockEngine for all the ClassMolderfactory
- factory class for getting Persistent of the ClassMolder
- Vector of all of the ClassMolders from a MappingLoader
revertObject
public void revertObject(TransactionContext tx,
OID oid,
DepositBox locker,
Object object)
throws PersistenceException
Revert the object back to the state of begining of the transaction
If the object is loaded, it will be revert as it was loaded. If the
object is created, it will be revert as it was just created.
tx
- - transaction in actionoid
- - the object identity of the target objectlocker
- - the dirty checking cache of the target objectobject
- - the target object
setDepends
(package private) void setDepends(ClassMolder dep)
Mutator method to set the depends ClassMolder
setExtends
(package private) void setExtends(ClassMolder ext)
Mutator method to set the extends ClassMolder
setFieldsNull
public void setFieldsNull(Object object)
Set all persistence fields of object of the base type to null.
setIdentity
public void setIdentity(TransactionContext tx,
Object object,
Object identity)
throws PersistenceException
Set the identity into an object
tx
- the transaction contextobject
- the object to set the identityidentity
- the new identity for the object
setPersistence
public void setPersistence(Persistence persist)
Mutator method to set the PersistenceEngine of
toString
public String toString()
update
public boolean update(TransactionContext tx,
OID oid,
DepositBox locker,
Object object,
AccessMode suggestedAccessMode)
throws PersistenceException,
ObjectModifiedException
Update the object which loaded or created in the other transaction to
the persistent storage.
tx
- Transaction in actionoid
- the object identity of the stored objectlocker
- the dirty check cache of the objectobject
- the object to be stored
- boolean true if the updating object should be created
updateCache
public void updateCache(TransactionContext tx,
OID oid,
DepositBox locker,
Object object)
Update the dirty checking cache. This method is called after a transaction completed successfully.
tx
- - transaction in actionoid
- - object's identity of the target objectlocker
- - the dirty checking cache of the target objectobject
- - the target object
writeLock
public void writeLock(TransactionContext tx,
OID oid,
DepositBox locker,
Object object)
throws PersistenceException
Acquire a write lock on an object of the base type with the specified
identity from the persistence storage.
tx
- - Transaction in actionoid
- - the object identity of the target objectlocker
- - the dirty checking cache of the objectobject
- - the target object