com.antelmann.db
Interface TransactionListener

All Known Implementing Classes:

DBClassStoreCache, DBTransactionStoreAdapter, LoggerTransactionListener, TransactionCounter, TransactionListener.Adapter, UserTransactionListener

public interface TransactionListener

listens for DBTransaction changes and can potentially intervene upon preparing for a commit. This interface may also be used to provide rudimentary XA support.

Author:

Holger Antelmann

See Also:

DBTransaction, DatabaseChangeMonitor, DBStoreListener, Database

Nested Class Summary

static class

TransactionListener.Adapter provides convenient empty implementations for all methods

Method Summary

void	finishTransaction(DBTransaction transaction) called before the transaction commits (and before prepareToCommit(DBTransaction)), so that the commit at the database level can be prevented by throwing a DatabaseException here.
void	prepareToCommit(DBTransaction transaction) called right before the transaction actually commits and after finishTransaction(DBTransaction).
void	transactionAborted(DBTransaction transaction) called after a database transaction was aborted; the transaction is already inactive.
void	transactionBegin(DBTransaction transaction) called upon beginning a transaction (the transaction is already active)
void	transactionCommitted(DBTransaction transaction) called after a successful database commit; the transaction is already inactive.

Method Detail

transactionBegin

void transactionBegin(DBTransaction transaction)

called upon beginning a transaction (the transaction is already active)

finishTransaction

void finishTransaction(DBTransaction transaction)
                       throws DatabaseException

called before the transaction commits (and before prepareToCommit(DBTransaction)), so that the commit at the database level can be prevented by throwing a DatabaseException here. This method can also be used to make some updates on another database or checking on certain data before the transaction is allowed to commit. In other words, this method may effectively veto the commit of a transaction After this call, the transaction is soon either going to be committed or aborted (right after all listeners have been called). As this method runs within the transaction, it is possible to access/update any resources from the database.

Throws:

DatabaseException

prepareToCommit

void prepareToCommit(DBTransaction transaction)

called right before the transaction actually commits and after finishTransaction(DBTransaction). Any exception thrown is ignored; listeners must not do any lengthy operations here. This may be used for supporting the implementation of a 2-phase-commit.

Parameters:

transaction - the transaction (being still active) that is about to be committed

transactionCommitted

@Warning(value="do not directly start a new transaction when implementing this method")
void transactionCommitted(DBTransaction transaction)

called after a successful database commit; the transaction is already inactive. Note that you cannot start a new transaction within the call of this method, since subsequent listeners would not have a chance to react on this transaction end. If the implementation of this method tries to begin a new transaction, a TransactionException will be thrown. If you need to access/update resources of this database from this method, start a new thread that opens a new transaction.

transactionAborted

@Warning(value="do not directly start a new transaction when implementing this method")
void transactionAborted(DBTransaction transaction)

called after a database transaction was aborted; the transaction is already inactive. Note that you cannot to start a new transaction within the call of this method, since subsequent listeners would not have a chance to react on this transaction end. If the implementation of this method tries to begin a new transaction, a TransactionException will be thrown. If you need to access/update resources of this database from this method, start a new thread that opens a new transaction.