Class BSHTransactionParticipant

java.lang.Object

org.jpos.util.SimpleLogSource

org.jpos.transaction.participant.BSHTransactionParticipant

All Implemented Interfaces:

XmlConfigurable, AbortParticipant, TransactionConstants, TransactionParticipant, LogSource

Direct Known Subclasses:

BSHGroupSelector

public class BSHTransactionParticipant
extends SimpleLogSource
implements TransactionParticipant, AbortParticipant, XmlConfigurable

A TransactionParticipant whose prepare, commit and abort methods can be specified through beanshell scripts.
To indicate what code to execute for any of the methods just add an element named 'prepare', 'commit' or 'abort' contained in that of the participant.
See BSHMethod for details on the syntax of these elements. The value to return in the prepare method should be stored in the script variable named "result". None of these tags are mandatory.
You can subclass BSHTransactionParticipant and override the default... methods. That way you can provide default behaviour for a participant and override it at deploy time through scripts.

See Also:

• BSHMethod

Field Summary

Fields

Modifier and Type	Field	Description
protected BSHMethod	abortMethod	BeanShell method for the abort phase.
protected BSHMethod	commitMethod	BeanShell method for the commit phase.
protected BSHMethod	prepareForAbortMethod	BeanShell method for the prepare-for-abort phase.
protected BSHMethod	prepareMethod	BeanShell method for the prepare phase.

Fields inherited from class SimpleLogSource

logger, realm

Modifier and Type	Field	Description
protected Logger	logger	The logger used by this log source.
protected String	realm	The logging realm for this log source.

Fields inherited from interface TransactionConstants

ABORTED, FAIL, NO_JOIN, PAUSE, PREPARED, READONLY, RETRY

Modifier and Type	Field	Description
static final int	ABORTED	Transaction has been aborted.
static final int	FAIL	Shortcut for a read-only, non-joining abort (READONLY | NO_JOIN).
static final int	NO_JOIN	This participant does not join the transaction
static final int	PAUSE	Transaction is paused.
static final int	PREPARED	Transaction has been prepared successfully.
static final int	READONLY	Context has not been modified (no need to persist a snapshot)
static final int	RETRY	Transaction should be retried.

Constructor Summary

Constructors

Constructor	Description
BSHTransactionParticipant()	Creates a new instance of BSHTransactionParticipant

Method Summary

Modifier and Type	Method	Description
void	abort(long id, Serializable context)	Called by TransactionManager upon transaction commit.
void	commit(long id, Serializable context)	Called by TransactionManager upon transaction commit.
protected void	defaultAbort(long id, Serializable context, LogEvent ev)	Default abort handling when no BeanShell abort method is configured (no-op).
protected void	defaultCommit(long id, Serializable context, LogEvent ev)	Default commit implementation (no-op).
protected int	defaultPrepare(long id, Serializable context, LogEvent ev)	Default prepare implementation; returns PREPARED|READONLY.
protected Object	executeMethod(BSHMethod m, long id, Serializable context, LogEvent evt, String resultName)	Executes the given BSHMethod with the standard transaction parameters.
int	prepare(long id, Serializable context)	Called by TransactionManager in preparation for a transaction
int	prepareForAbort(long id, Serializable context)	Called by TransactionManager in preparation for a transaction that is known to abort.
void	setConfiguration(org.jdom2.Element e)	Configures this object from an XML element.

Methods inherited from class SimpleLogSource

error, error, getLogger, getRealm, info, info, setLogger, setRealm, warning, warning

Modifier and Type	Method	Description
void	error(String detail)	Logs an error message.
void	error(String detail, Object obj)	Logs an error message with an attached object.
Logger	getLogger()	Returns the logger.
String	getRealm()	Returns the logging realm.
void	info(String detail)	Logs an informational message.
void	info(String detail, Object obj)	Logs an informational message with an attached object.
void	setLogger(Logger logger, String realm)	Sets the logger and realm for this log source.
void	setRealm(String realm)	Sets the logging realm.
void	warning(String detail)	Logs a warning message.
void	warning(String detail, Object obj)	Logs a warning message with an attached object.

Methods inherited from class Object

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

Field Details

prepareMethod

protected BSHMethod prepareMethod

BeanShell method for the prepare phase.

prepareForAbortMethod

protected BSHMethod prepareForAbortMethod

BeanShell method for the prepare-for-abort phase.

commitMethod

protected BSHMethod commitMethod

BeanShell method for the commit phase.

abortMethod

protected BSHMethod abortMethod

BeanShell method for the abort phase.

Constructor Details

BSHTransactionParticipant

public BSHTransactionParticipant()

Creates a new instance of BSHTransactionParticipant

Method Details

abort

public void abort(long id,
 Serializable context)

Description copied from interface: TransactionParticipant

Called by TransactionManager upon transaction commit. Warning: implementation should be able to handle multiple calls with the same transaction id (rare crash recovery)

Specified by:

abort in interface TransactionParticipant

Parameters:

id - the Transaction identifier

context - transaction context

defaultAbort

protected void defaultAbort(long id,
 Serializable context,
 LogEvent ev)

Default abort handling when no BeanShell abort method is configured (no-op).

Parameters:

id - transaction id

context - transaction context

ev - log event

commit

public void commit(long id,
 Serializable context)

Description copied from interface: TransactionParticipant

Called by TransactionManager upon transaction commit. Warning: implementation should be able to handle multiple calls with the same transaction id (rare crash recovery)

Specified by:

commit in interface TransactionParticipant

Parameters:

id - the Transaction identifier

context - transaction context

defaultCommit

protected void defaultCommit(long id,
 Serializable context,
 LogEvent ev)

Default commit implementation (no-op).

Parameters:

id - transaction id

context - transaction context

ev - log event

prepare

public int prepare(long id,
 Serializable context)

Description copied from interface: TransactionParticipant

Called by TransactionManager in preparation for a transaction

Specified by:

prepare in interface TransactionParticipant

Parameters:

id - the Transaction identifier

context - transaction context

Returns:

PREPARED or ABORTED (| NO_JOIN | READONLY)

prepareForAbort

public int prepareForAbort(long id,
 Serializable context)

Called by TransactionManager in preparation for a transaction that is known to abort.

Specified by:

prepareForAbort in interface AbortParticipant

Parameters:

id - the Transaction identifier

context - transaction context

Returns:

0 [| NO_JOIN | READONLY)

defaultPrepare

protected int defaultPrepare(long id,
 Serializable context,
 LogEvent ev)

Default prepare implementation; returns PREPARED|READONLY.

Parameters:

id - transaction id

context - transaction context

ev - log event

Returns:

transaction result code

setConfiguration

public void setConfiguration(org.jdom2.Element e)
                      throws ConfigurationException

Description copied from interface: XmlConfigurable

Configures this object from an XML element.

Specified by:

setConfiguration in interface XmlConfigurable

Parameters:

e - Configuration element

Throws:

ConfigurationException - on error

executeMethod

protected Object executeMethod(BSHMethod m,
 long id,
 Serializable context,
 LogEvent evt,
 String resultName)
                        throws bsh.EvalError,
IOException

Executes the given BSHMethod with the standard transaction parameters.

Parameters:

m - the BSHMethod to execute

id - transaction id

context - transaction context

evt - log event

resultName - the result variable name

Returns:

the value of resultName after execution

Throws:

bsh.EvalError - on BeanShell evaluation error

IOException - if the script cannot be read