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

Methods inherited from interface org.alfresco.util.transaction.TransactionListener

getCustomOrder

Constructor Details

TransactionAwareSingleton

public TransactionAwareSingleton()

Method Details

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