com.sun.jdo.spi.persistence.support.sqlstore.ejb

Class TransactionHelperImpl

java.lang.Object

com.sun.jdo.spi.persistence.support.sqlstore.ejb.TransactionHelperImpl

All Implemented Interfaces:

TransactionHelper

Direct Known Subclasses:

SunTransactionHelper

public abstract class TransactionHelperImpl
extends Object
implements TransactionHelper

This is an abstract class which is a generic implementation of the TransactionHelper interface. Each concrete implementation that extends this class is used for information about the distributed transaction environment. The class that extends this class must implement getTransaction and getUserTransaction methods and replace any other method implementation if it is necessary. Such class must register itself by a static method at class initialization time. For example,

 import com.sun.jdo.spi.persistence.support.sqlstore.ejb.*;
 class blackHerringTransactionHelper extends TransactionHelperImpl {
    static EJBHelper.register(new blackHerringTransactionHelper());
    ...
 } 
 

Constructor Summary

Constructors

Constructor and Description
TransactionHelperImpl()

Method Summary

Modifier and Type	Method and Description
Connection	getConnection(Object resource, String username, char[] password) Called in a managed environment to get a Connection from the application server specific resource.
String	getDDLNamePrefix(Object info) Returns name prefix for DDL files extracted from the info instance by the application server specific code.
abstract TransactionManager	getLocalTransactionManager() Called in a managed environment to access a TransactionManager for managing local transaction boundaries and registering synchronization for call backs during completion of a local transaction.
abstract Connection	getNonTransactionalConnection(Object resource, String username, char[] password) Called in a managed environment to get a non-transactional Connection from the application server specific resource.
abstract Transaction	getTransaction() Identify the Transaction context for the calling thread, and return a Transaction instance that can be used to register synchronizations, and used as the key for HashMaps.
abstract UserTransaction	getUserTransaction() Returns the UserTransaction associated with the calling thread.
boolean	isManaged() Identifies the managed environment behavior.
void	notifyApplicationUnloaded(ClassLoader cl) Called to notify a ApplicationLifeCycleEventListeners that an application is unloaded.
void	postInvoke(Object im) Called at the end of the Transaction.beforeCompletion() to de-register the component with the app server if necessary.
Object	preInvoke(Object component) Called at the beginning of the Transaction.beforeCompletion() to register the component with the app server only if necessary.
void	registerApplicationLifeCycleEventListener(ApplicationLifeCycleEventListener listener) Called to register a ApplicationLifeCycleEventListener.
void	registerSynchronization(Transaction jta, Synchronization sync) Called in a managed environment to register internal Synchronization object with the Transaction Synchronization.
PersistenceManagerFactory	replaceInternalPersistenceManagerFactory(PersistenceManagerFactory pmf) Replace newly created instance of PersistenceManagerFactory with the hashed one if it exists.
void	setPersistenceManagerFactoryDefaults(PersistenceManagerFactory pmf) Set environment specific default values for the given PersistenceManagerFactory.
int	translateStatus(int st) Translate local representation of the Transaction Status to javax.transaction.Status value if necessary.
Statement	unwrapStatement(Statement stmt) This method unwraps given Statement and return the Statement from JDBC driver if possible.

Methods inherited from class java.lang.Object

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

Constructor Detail

TransactionHelperImpl

public TransactionHelperImpl()

Method Detail

isManaged

public boolean isManaged()

Identifies the managed environment behavior.

Specified by:

isManaged in interface TransactionHelper

Returns:

true as this implementation represents the managed environment.

getTransaction

public abstract Transaction getTransaction()

Identify the Transaction context for the calling thread, and return a Transaction instance that can be used to register synchronizations, and used as the key for HashMaps. The returned Transaction must implement equals() and hashCode() based on the global transaction id.

All Transaction instances returned by this method called in the same Transaction context must compare equal and return the same hashCode. The Transaction instance returned will be held as the key to an internal HashMap until the Transaction completes. If there is no transaction associated with the current thread, this method returns null.

Specified by:

getTransaction in interface TransactionHelper

Returns:

the Transaction instance for the calling thread

getUserTransaction

public abstract UserTransaction getUserTransaction()

Returns the UserTransaction associated with the calling thread. If there is no transaction currently in progress, this method returns null.

Specified by:

getUserTransaction in interface TransactionHelper

Returns:

the UserTransaction instance for the calling thread

translateStatus

public int translateStatus(int st)

Translate local representation of the Transaction Status to javax.transaction.Status value if necessary. Otherwise this method should return the value passed to it as an argument.

This method is used during afterCompletion callbacks to translate the parameter value passed by the application server to the afterCompletion method. The return value must be one of: javax.transaction.Status.STATUS_COMMITTED or javax.transaction.Status.STATUS_ROLLED_BACK.

Specified by:

translateStatus in interface TransactionHelper

Parameters:

st - local Status value

Returns:

the javax.transaction.Status value of the status

replaceInternalPersistenceManagerFactory

public PersistenceManagerFactory replaceInternalPersistenceManagerFactory(PersistenceManagerFactory pmf)

Replace newly created instance of PersistenceManagerFactory with the hashed one if it exists. The replacement is necessary only if the JNDI lookup always returns a new instance. Otherwise this method returns the object passed to it as an argument. PersistenceManagerFactory is uniquely identified by ConnectionFactory.hashCode() if ConnectionFactory is not null; otherwise by ConnectionFactoryName.hashCode() if ConnectionFactoryName is not null; otherwise by the combination of URL.hashCode() + userName.hashCode() + password.hashCode() + driverName.hashCode();

Specified by:

replaceInternalPersistenceManagerFactory in interface TransactionHelper

Parameters:

pmf - PersistenceManagerFactory instance to be replaced

Returns:

the PersistenceManagerFactory known to the runtime

preInvoke

public Object preInvoke(Object component)

Called at the beginning of the Transaction.beforeCompletion() to register the component with the app server only if necessary. The component argument is an array of Objects. The first element is com.sun.jdo.spi.persistence.support.sqlstore.Transaction object responsible for transaction completion. The second element is com.sun.jdo.api.persistence.support.PersistenceManager object that has been associated with the Transaction context for the calling thread. The third element is javax.transaction.Transaction object that has been associated with the given instance of PersistenceManager. The return value is passed unchanged to the postInvoke method.

Specified by:

preInvoke in interface TransactionHelper

Parameters:

component - an array of Objects

Returns:

implementation-specific Object

postInvoke

public void postInvoke(Object im)

Called at the end of the Transaction.beforeCompletion() to de-register the component with the app server if necessary. The parameter is the return value from preInvoke, and can be any Object.

Specified by:

postInvoke in interface TransactionHelper

Parameters:

im - implementation-specific Object

registerSynchronization

public void registerSynchronization(Transaction jta,
                                    Synchronization sync)
                             throws RollbackException,
                                    SystemException

Called in a managed environment to register internal Synchronization object with the Transaction Synchronization. If available, this registration provides special handling of the registered instance, calling it after all user defined Synchronization instances.

Specified by:

registerSynchronization in interface TransactionHelper

Parameters:

jta - the Transaction instance for the calling thread.

sync - the internal Synchronization instance to register.

Throws:

javax.transaction.RollbackException.

SystemException

RollbackException

getConnection

public Connection getConnection(Object resource,
                                String username,
                                char[] password)
                         throws SQLException

Called in a managed environment to get a Connection from the application server specific resource. In a non-managed environment returns null as it should not be called. This is a generic implementation for the case of javax.sql.DataSource as the resource type.

Specified by:

getConnection in interface TransactionHelper

Parameters:

resource - the application server specific resource.

username - the resource username. If null, Connection is requested without username and password validation.

password - the password for the resource username.

Returns:

a Connection.

Throws:

java.sql.SQLException.

SQLException

getNonTransactionalConnection

public abstract Connection getNonTransactionalConnection(Object resource,
                                                         String username,
                                                         char[] password)
                                                  throws SQLException

Called in a managed environment to get a non-transactional Connection from the application server specific resource.

Specified by:

getNonTransactionalConnection in interface TransactionHelper

Parameters:

resource - the application server specific resource.

username - the resource username. If null, Connection is requested without username and password validation.

password - the password for the resource username.

Returns:

a Connection.

Throws:

java.sql.SQLException.

SQLException

getLocalTransactionManager

public abstract TransactionManager getLocalTransactionManager()

Called in a managed environment to access a TransactionManager for managing local transaction boundaries and registering synchronization for call backs during completion of a local transaction.

Specified by:

getLocalTransactionManager in interface TransactionHelper

Returns:

javax.transaction.TransactionManager

unwrapStatement

public Statement unwrapStatement(Statement stmt)

This method unwraps given Statement and return the Statement from JDBC driver if possible.

Specified by:

unwrapStatement in interface TransactionHelper

setPersistenceManagerFactoryDefaults

public void setPersistenceManagerFactoryDefaults(PersistenceManagerFactory pmf)

Set environment specific default values for the given PersistenceManagerFactory. In most app servers optimistic and retainValues flags should be false. For any other settings this method should be overritten.

Specified by:

setPersistenceManagerFactoryDefaults in interface TransactionHelper

Parameters:

pmf - the PersistenceManagerFactory.

getDDLNamePrefix

public String getDDLNamePrefix(Object info)

Returns name prefix for DDL files extracted from the info instance by the application server specific code.

Specified by:

getDDLNamePrefix in interface TransactionHelper

Parameters:

info - the instance to use for the name generation.

Returns:

name prefix as String.

registerApplicationLifeCycleEventListener

public void registerApplicationLifeCycleEventListener(ApplicationLifeCycleEventListener listener)

Description copied from interface: TransactionHelper

Called to register a ApplicationLifeCycleEventListener. If ApplicationLifeCycle management is active (typically in managed environment), the registered listener will receive a call back for lifecycle events.

Specified by:

registerApplicationLifeCycleEventListener in interface TransactionHelper

Parameters:

listener - An instance of ApplicationLifeCycleEventListener.

notifyApplicationUnloaded

public void notifyApplicationUnloaded(ClassLoader cl)

Description copied from interface: TransactionHelper

Called to notify a ApplicationLifeCycleEventListeners that an application is unloaded. If ApplicationLifeCycle management is active (typically in managed environment), the registered listener will handle the notification.

Specified by:

notifyApplicationUnloaded in interface TransactionHelper

Parameters:

cl - An instance of the ClassLoader that loaded the application.