de.schwarzrot.data.transaction
Class ApplicationTransaction

java.lang.Object
  de.schwarzrot.data.transaction.ApplicationTransaction

All Implemented Interfaces:

Transaction

public class ApplicationTransaction
extends Object
implements Transaction

An ApplicationTransaction is a wrapper around TransactionalOperations, which can be added to setup a transaction. The transaction is then executed by the Repository and so the transaction may span different persistent resources, but the application does not need to care about those resources nor does it need to know, which resource is involved.

The application only adds an Entity or several entities together with the opcode, which should be applied to that entities.

So, the enlisting/delisting of resources is internal to the transaction processor, which in this case is the Repository.

This transaction implements a VetoableChangeSupport for changes of the transaction status. These status values are vetoable:

• STATUS_ACTIVE
• STATUS_COMMITTING
• STATUS_PREPARING
• STATUS_ROLLING_BACK

Any veto on other status changes is silently ignored.

Author:

Reinhard Mantey

Constructor Summary

ApplicationTransaction()

Method Summary

void	add(TransactionalOperation<?> tao) used to add an operation to the transaction.
void	addVetoableStatusListener(VetoableChangeListener listener) add vetoable change listener to the transaction.
void	execute() executes all added operations
TransactionalOperation.DataDirection	getDataDirection() internal use only.
List<TransactionalOperation<?>>	getOperations() internal use only.
TransactionResource<?>	getResource(EntityManager em) internal use only.
TransactionStatus	getStatus() accessor to the transactions status
boolean	isEntityManagerRegistered(EntityManager em) internal use only.
boolean	isRollbackOnly() internal use only.
Collection<EntityManager>	registeredManagers() internal use only.
void	registerResource(EntityManager em, TransactionResource<?> res) internal use only.
void	setRollbackOnly() use this, if the transaction does only read operations.
void	setStatus(TransactionStatus ts) internal use only.

Methods inherited from class java.lang.Object

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

Constructor Detail

ApplicationTransaction

public ApplicationTransaction()

Method Detail

add

public void add(TransactionalOperation<?> tao)

Description copied from interface: Transaction

used to add an operation to the transaction.

Specified by:

add in interface Transaction

Parameters:

tao - the operation to add to the transaction

addVetoableStatusListener

public void addVetoableStatusListener(VetoableChangeListener listener)

Description copied from interface: Transaction

add vetoable change listener to the transaction. TransationStatus is the property guarded by the change listeners, so a listener can throw its veto on each status change. Any veto will result in a rollback of the transaction.

Specified by:

addVetoableStatusListener in interface Transaction

Parameters:

listener - - the listener to add

execute

public void execute()

Description copied from interface: Transaction

executes all added operations

Specified by:

execute in interface Transaction

getDataDirection

public TransactionalOperation.DataDirection getDataDirection()

Description copied from interface: Transaction

internal use only.. Is used by the EntityManager to open the TransactionResource in an appropriate way.

Specified by:

getDataDirection in interface Transaction

getOperations

public List<TransactionalOperation<?>> getOperations()

Description copied from interface: Transaction

internal use only.. Is used by the Repository

Specified by:

getOperations in interface Transaction

Returns:

the defined operations

getResource

public TransactionResource<?> getResource(EntityManager em)

Description copied from interface: Transaction

internal use only.. Is used by the Repository

Specified by:

getResource in interface Transaction

Parameters:

em - the EntityManager, that created that resource

Returns:

the registered TransactionResource

getStatus

public TransactionStatus getStatus()

Description copied from interface: Transaction

accessor to the transactions status

Specified by:

getStatus in interface Transaction

Returns:

the status of the transaction

isEntityManagerRegistered

public boolean isEntityManagerRegistered(EntityManager em)

Description copied from interface: Transaction

internal use only.. Is used by the Repository

Specified by:

isEntityManagerRegistered in interface Transaction

Parameters:

em - the EntityManager of interest

Returns:

true, if the EntityManager has been used in a previous operation, otherwise false

isRollbackOnly

public boolean isRollbackOnly()

Description copied from interface: Transaction

internal use only.. Is used by the Repository

Specified by:

isRollbackOnly in interface Transaction

Returns:

whether this transaction has been marked for rollback

registeredManagers

public Collection<EntityManager> registeredManagers()

Description copied from interface: Transaction

internal use only.. Is used by the Repository

Specified by:

registeredManagers in interface Transaction

Returns:

all registered EntityManagers

registerResource

public void registerResource(EntityManager em,
                             TransactionResource<?> res)

Description copied from interface: Transaction

internal use only.. Is used by the Repository

Specified by:

registerResource in interface Transaction

Parameters:

em - the EntityManager, that created the TransactionResource

res - the created TransactionResource

setRollbackOnly

public void setRollbackOnly()

Description copied from interface: Transaction

use this, if the transaction does only read operations. May save some resources, depending on the bound Entity

Specified by:

setRollbackOnly in interface Transaction

setStatus

public void setStatus(TransactionStatus ts)
               throws PropertyVetoException

Description copied from interface: Transaction

internal use only.. Is used by the Repository

Specified by:

setStatus in interface Transaction

Parameters:

ts - the new status

Throws:

PropertyVetoException