Package org.alfresco.repo.transaction

Class TransactionAwareSingleton<T>

java.lang.Object

org.alfresco.repo.transaction.TransactionListenerAdapter

org.alfresco.repo.transaction.TransactionAwareSingleton<T>

All Implemented Interfaces:

TransactionListener, org.alfresco.util.transaction.TransactionListener

public class TransactionAwareSingleton<T>
extends TransactionListenerAdapter

A transactionally-safe storage class for singleton objects. Changes to the singleton are only visibly promoted when the transaction is committed.

private static final TransactionAwareSingleton MY_SINGLETON = new TransactionAwareSingleton();

All modifications to the singleton via get() and put(Object) are made in a transaction-local manner and promoted to the shared value in a thread-safe manner upon transacton completion. Transaction-local changes take precedence over the shared value.

Author:

Derek Hulley

See Also:

AlfrescoTransactionSupport

Constructor Summary

Constructors

Constructor	Description
TransactionAwareSingleton()

Method Summary

Modifier and Type	Method	Description
void	afterCommit()	Promotes the storage value to the single value, if required
T	get()
void	put(T value)	Store the value in a transaction- and thread-safe manner.

Methods inherited from class org.alfresco.repo.transaction.TransactionListenerAdapter

afterRollback, beforeCommit, beforeCompletion, flush

Methods inherited from class java.lang.Object

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

Constructor Detail

TransactionAwareSingleton

public TransactionAwareSingleton()

Method Detail

get

public T get()

Returns:

Returns the transaction- and thread-safe wrapped instance

put

public void put(T value)

Store the value in a transaction- and thread-safe manner. It will only be persisted at the end of the transaction but will be visible to the current transaction from this call onwards.

Parameters:

value - the value to store

afterCommit

public void afterCommit()

Promotes the storage value to the single value, if required

Specified by:

afterCommit in interface TransactionListener

Specified by:

afterCommit in interface org.alfresco.util.transaction.TransactionListener

Overrides:

afterCommit in class TransactionListenerAdapter