com.antelmann.db
Class TransactionCounter

java.lang.Object
  com.antelmann.db.TransactionListener.Adapter
      com.antelmann.db.TransactionCounter

All Implemented Interfaces:

TransactionListener

public class TransactionCounter
extends TransactionListener.Adapter

A TransactionCounter increments its counter upon transaction begin to allow determining whether it's still the same transaction. This counter allows to determine whether an ongoing transaction of a given database is still the same as during a previous call by checking the counter.

Since:

21. Oktober 2007, 22:33

Author:

Holger Antelmann

See Also:

getTransactionCounter(DBTransaction)

Nested Class Summary

Nested classes/interfaces inherited from interface com.antelmann.db.TransactionListener

TransactionListener.Adapter

Constructor Summary

TransactionCounter(DBTransaction ta)
After calling the constructor, this instance must still be added as a listener to the given transaction before the counter works.

Method Summary

void	checkCount(int count)
int	getCounter()
DBTransaction	getTransaction()
static TransactionCounter	getTransactionCounter(DBTransaction ta) returns a TransactionCounter associated and listening to the given DBTransaction.
void	transactionBegin(DBTransaction transaction) increments the counter by one if the given transaction is the same as the embedded one

Methods inherited from class com.antelmann.db.TransactionListener.Adapter

finishTransaction, prepareToCommit, transactionAborted, transactionCommitted

Methods inherited from class java.lang.Object

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

Constructor Detail

TransactionCounter

public TransactionCounter(DBTransaction ta)

After calling the constructor, this instance must still be added as a listener to the given transaction before the counter works. Also, it must then be removed as a listener to be garbage-collected. Preferably, use getTransactionCounter(DBTransaction) to only have one counter per database.

Method Detail

getTransaction

public DBTransaction getTransaction()

getCounter

public int getCounter()

checkCount

public void checkCount(int count)
                throws TransactionException

Throws:

TransactionException

transactionBegin

public void transactionBegin(DBTransaction transaction)

increments the counter by one if the given transaction is the same as the embedded one

Specified by:

transactionBegin in interface TransactionListener

Overrides:

transactionBegin in class TransactionListener.Adapter

getTransactionCounter

public static TransactionCounter getTransactionCounter(DBTransaction ta)

returns a TransactionCounter associated and listening to the given DBTransaction. First, this method seeks to find an existing TransactionCounter already used as a listener; if found, that one is simply returned. If that fails, a new TransactionCounter instance is created, added as a listener to the database, and returned.

See Also:

AbstractDBTransaction.getTransactionListeners()