Package com.ibm.fhir.database.utils.pool

Class PoolConnectionProvider

java.lang.Object

com.ibm.fhir.database.utils.pool.PoolConnectionProvider

All Implemented Interfaces:

IConnectionProvider

public class PoolConnectionProvider
extends Object
implements IConnectionProvider

Provides a simple connection pool with some thread-local behavior so that requests for a connection within the same thread will get the same connection back. Cooperates with the TransactionFactory to provide a JEE-flavored experience, and makes it easy to write code which will work in both J2SE and JEE environments. Does not support distributed transactions.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) int	allocated

Constructor Summary

Constructors

Constructor	Description
PoolConnectionProvider(IConnectionProvider cp, int maxPoolSize)	Public constructor

Method Summary

Modifier and Type	Method	Description
protected boolean	checkConnectionFailure(SQLException x)	Simple check to see if the exception is related to a connection error, in which case the connection shouldn't be returned to the pool when closed
protected void	clearActiveConnection()	Remove the active connection on this thread.
void	close()	The caller is telling us they no longer need to use the pool so we can free any internal resources.
void	commitTransaction()	Commit the current transaction if there's an actual connection associated with this thread (i.e.
void	describe(String prefix, StringBuilder cfg, String key)	Describe self, for writing configuration information to log file for test record purposes
Connection	getConnection()	Obtain a new connection to a data-source which this provider has been configured for.
int	getPoolSize()	gets the pool size for the pooled connection
IDatabaseTranslator	getTranslator()	Get the translator associated with this connection provider.
protected void	returnConnection(PooledConnection pc, boolean reuse)	Called when the connection is closed, which in this case is pretty much a NOP, because this connection will stay active on this thread until the transaction commits
void	rollbackTransaction()	Roll back the transaction for the connection associated with this thread, if one exists
void	setCloseOnAnyError()	Configure the pool to close connections after an error instead of returning them to the pool.

Methods inherited from class java.lang.Object

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

Field Detail

allocated

int allocated

Constructor Detail

PoolConnectionProvider

public PoolConnectionProvider(IConnectionProvider cp,
                              int maxPoolSize)

Public constructor

Parameters:

cp -

maxPoolSize -

Method Detail

setCloseOnAnyError

public void setCloseOnAnyError()

Configure the pool to close connections after an error instead of returning them to the pool. Exceptions related to connection errors will always mark the connection as no longer usable.

getConnection

public Connection getConnection()
                         throws SQLException

Description copied from interface: IConnectionProvider

Obtain a new connection to a data-source which this provider has been configured for.

Specified by:

getConnection in interface IConnectionProvider

Returns:

Throws:

SQLException

returnConnection

protected void returnConnection(PooledConnection pc,
                                boolean reuse)

Called when the connection is closed, which in this case is pretty much a NOP, because this connection will stay active on this thread until the transaction commits

Parameters:

pc -

clearActiveConnection

protected void clearActiveConnection()
                              throws SQLException

Remove the active connection on this thread. Called when the transaction completes

Throws:

SQLException

checkConnectionFailure

protected boolean checkConnectionFailure(SQLException x)

Simple check to see if the exception is related to a connection error, in which case the connection shouldn't be returned to the pool when closed

Parameters:

x -

Returns:

getTranslator

public IDatabaseTranslator getTranslator()

Description copied from interface: IConnectionProvider

Get the translator associated with this connection provider. Supports interpretation of SQLExceptions and the ability to tweak SQL statements to handle differences between DB2 and Derby

Specified by:

getTranslator in interface IConnectionProvider

Returns:

commitTransaction

public void commitTransaction()
                       throws SQLException

Description copied from interface: IConnectionProvider

Commit the current transaction if there's an actual connection associated with this thread (i.e. if getConnection() has been called at least once), otherwise do nothing.

Specified by:

commitTransaction in interface IConnectionProvider

Throws:

SQLException

rollbackTransaction

public void rollbackTransaction()
                         throws SQLException

Description copied from interface: IConnectionProvider

Roll back the transaction for the connection associated with this thread, if one exists

Specified by:

rollbackTransaction in interface IConnectionProvider

Throws:

SQLException

describe

public void describe(String prefix,
                     StringBuilder cfg,
                     String key)

Description copied from interface: IConnectionProvider

Describe self, for writing configuration information to log file for test record purposes

Specified by:

describe in interface IConnectionProvider

getPoolSize

public int getPoolSize()

gets the pool size for the pooled connection

Specified by:

getPoolSize in interface IConnectionProvider

close

public void close()

The caller is telling us they no longer need to use the pool so we can free any internal resources. This also let's us check for anything currently in-use that shouldn't be

Throws:

IllegalStateException - if there are open connections or a transaction is active.