Class EmbedPooledConnection

java.lang.Object

org.apache.derby.jdbc.EmbedPooledConnection

All Implemented Interfaces:

PooledConnection, BrokeredConnectionControl

Direct Known Subclasses:

EmbedXAConnection

class EmbedPooledConnection
extends Object
implements PooledConnection, BrokeredConnectionControl

A PooledConnection object is a connection object that provides hooks for connection pool management.

This is Derby's implementation of a PooledConnection for use in the following environments:

• JDBC 4.2 - Java SE 8
• JDBC 4.1 - Java SE 7
• JDBC 4.0 - Java SE 6

Field Summary

Fields

Modifier and Type	Field	Description
private String	connString	the connection string
(package private) BrokeredConnection	currentConnectionHandle
(package private) final BasicEmbeddedDataSource40	dataSource
(package private) int	defaultIsolationLevel
private boolean	defaultReadOnly
private int	eventIterators	The number of iterators going through the list of connection event listeners at the current time.
private ArrayList<ConnectionEventListener>	eventListener	The list of ConnectionEventListeners.
protected boolean	isActive
private final String	password
(package private) EmbedConnection	realConnection
private final boolean	requestPassword	True if the password was passed in on the connection request, false if it came from the data source property.
private final CopyOnWriteArrayList<StatementEventListener>	statementEventListeners	List of statement event listeners.
private final String	username

Constructor Summary

Constructors

Constructor	Description
EmbedPooledConnection(BasicEmbeddedDataSource40 ds, String u, String p, boolean requestPassword)

Method Summary

Modifier and Type	Method	Description
final void	addConnectionEventListener(ConnectionEventListener listener)	Add an event listener.
void	addStatementEventListener(StatementEventListener listener)	Registers a StatementEventListener with this PooledConnection object.
(package private) final void	checkActive()
void	checkAutoCommit(boolean autoCommit)	Allow control over setting auto commit mode.
void	checkClose()	Check if the brokered connection can be closed.
void	checkCommit()	Allow control over calling commit.
int	checkHoldCursors(int holdability, boolean downgrade)	Are held cursors allowed.
void	checkRollback()	Allow control over calling rollback.
void	checkSavepoint()	Allow control over creating a Savepoint (JDBC 3.0)
void	close()	Close the Pooled connection.
private void	closeCurrentConnectionHandle()	In this case the Listeners are *not* notified.
boolean	closingConnection()	Close called on BrokeredConnection.
private void	fireConnectionEventListeners(SQLException exception)	Fire all the ConnectionEventListeners registered.
Connection	getConnection()	Create an object handle for a database connection.
LanguageConnectionContext	getLanguageConnection()
private static LanguageConnectionContext	getLanguageConnectionContext(EmbedConnection conn)	Gets the LanguageConnectionContext for this connection.
(package private) final Connection	getNewCurrentConnectionHandle()
(package private) String	getPassword()
EngineConnection	getRealConnection()	Return the real JDBC connection for the brokered connection.
(package private) String	getUsername()
boolean	isActive()	getter function for isActive
boolean	isInGlobalTransaction()	Is this a global transaction
boolean	isIsolationLevelSetUsingSQLorJDBC()	Returns true if isolation level has been set using either JDBC api or SQL
void	notifyError(SQLException exception)
void	notifyException(SQLException sqle)	Notify the control class that a SQLException was thrown during a call on one of the brokered connection's methods.
void	onStatementClose(PreparedStatement statement)	Raise the statementClosed event for all the listeners when the corresponding events occurs
void	onStatementErrorOccurred(PreparedStatement statement, SQLException sqle)	Raise the statementErrorOccurred event for all the listeners when the corresponding events occurs
(package private) final void	openRealConnection()
final void	removeConnectionEventListener(ConnectionEventListener listener)	Remove an event listener.
void	removeStatementEventListener(StatementEventListener listener)	Removes the specified StatementEventListener from the list of components that will be notified when the driver detects that a PreparedStatement has been closed or is invalid.
void	resetIsolationLevelFlag()	Reset the isolation level flag used to keep state in BrokeredConnection.
(package private) void	resetRealConnection()
String	toString()	Get the string representation of this pooled connection.
CallableStatement	wrapStatement(CallableStatement cs, String sql)	Call the setBrokeredConnectionControl method inside the EmbedCallableStatement class to set the BrokeredConnectionControl variable to this instance of EmbedPooledConnection This will then be used to call the onStatementErrorOccurred and onStatementClose events when the corresponding events occur on the CallableStatement
PreparedStatement	wrapStatement(PreparedStatement ps, String sql, Object generatedKeys)	Call the setBrokeredConnectionControl method inside the EmbedPreparedStatement class to set the BrokeredConnectionControl variable to this instance of EmbedPooledConnection This will then be used to call the onStatementErrorOccurred and onStatementClose events when the corresponding events occur on the PreparedStatement
Statement	wrapStatement(Statement s)	No need to wrap statements for PooledConnections.

Methods inherited from class Object

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

Field Details

connString

private String connString

the connection string

eventListener

private ArrayList<ConnectionEventListener> eventListener

The list of ConnectionEventListeners. It is initially null and will be initialized lazily when the first listener is added.

statementEventListeners

private final CopyOnWriteArrayList<StatementEventListener> statementEventListeners

List of statement event listeners. The list is copied on each write, ensuring that it can be safely iterated over even if other threads or the listeners fired in the same thread add or remove listeners.

eventIterators

private int eventIterators

The number of iterators going through the list of connection event listeners at the current time. Only one thread may be iterating over the list at any time (because of synchronization), but a single thread may have multiple iterators if for instance an event listener performs database calls that trigger a new event.

realConnection

EmbedConnection realConnection

defaultIsolationLevel

int defaultIsolationLevel

defaultReadOnly

private boolean defaultReadOnly

currentConnectionHandle

BrokeredConnection currentConnectionHandle

dataSource

final BasicEmbeddedDataSource40 dataSource

username

private final String username

password

private final String password

requestPassword

private final boolean requestPassword

True if the password was passed in on the connection request, false if it came from the data source property.

isActive

protected boolean isActive

Constructor Details

EmbedPooledConnection

EmbedPooledConnection(BasicEmbeddedDataSource40 ds,
 String u,
 String p,
 boolean requestPassword)
               throws SQLException

Throws:

SQLException

Method Details

isActive

public boolean isActive()

getter function for isActive

Returns:

boolean is isActive is true

getUsername

String getUsername()

getPassword

String getPassword()

getConnection

public Connection getConnection()
                         throws SQLException

Create an object handle for a database connection.

Specified by:

getConnection in interface PooledConnection

Returns:

a Connection object

Throws:

SQLException - - if a database-access error occurs.

openRealConnection

final void openRealConnection()
                       throws SQLException

Throws:

SQLException

getNewCurrentConnectionHandle

final Connection getNewCurrentConnectionHandle()
                                        throws SQLException

Throws:

SQLException

closeCurrentConnectionHandle

private void closeCurrentConnectionHandle()
                                   throws SQLException

In this case the Listeners are *not* notified. JDBC 3.0 spec section 11.4

Throws:

SQLException

resetRealConnection

void resetRealConnection()
                  throws SQLException

Throws:

SQLException

close

public void close()
           throws SQLException

Close the Pooled connection.

Specified by:

close in interface PooledConnection

Throws:

SQLException - - if a database-access error occurs.

addConnectionEventListener

public final void addConnectionEventListener(ConnectionEventListener listener)

Add an event listener.

Specified by:

addConnectionEventListener in interface PooledConnection

removeConnectionEventListener

public final void removeConnectionEventListener(ConnectionEventListener listener)

Remove an event listener.

Specified by:

removeConnectionEventListener in interface PooledConnection

getRealConnection

public EngineConnection getRealConnection()
                                   throws SQLException

Description copied from interface: BrokeredConnectionControl

Return the real JDBC connection for the brokered connection.

Specified by:

getRealConnection in interface BrokeredConnectionControl

Throws:

SQLException

getLanguageConnection

public LanguageConnectionContext getLanguageConnection()
                                                throws SQLException

Returns:

The underlying language connection.

Throws:

SQLException

notifyError

public void notifyError(SQLException exception)

fireConnectionEventListeners

private void fireConnectionEventListeners(SQLException exception)

Fire all the ConnectionEventListeners registered. Callers must synchronize on this to prevent others from modifying the list of listeners.

Parameters:

exception - the exception that caused the event, or null if it is a close event

checkActive

final void checkActive()
                throws SQLException

Throws:

SQLException

isIsolationLevelSetUsingSQLorJDBC

public boolean isIsolationLevelSetUsingSQLorJDBC()
                                          throws SQLException

Returns true if isolation level has been set using either JDBC api or SQL

Specified by:

isIsolationLevelSetUsingSQLorJDBC in interface BrokeredConnectionControl

Throws:

SQLException

resetIsolationLevelFlag

public void resetIsolationLevelFlag()
                             throws SQLException

Reset the isolation level flag used to keep state in BrokeredConnection. It will get set to true when isolation level is set using JDBC/SQL. It will get reset to false at the start and the end of a global transaction.

Specified by:

resetIsolationLevelFlag in interface BrokeredConnectionControl

Throws:

SQLException

isInGlobalTransaction

public boolean isInGlobalTransaction()

Description copied from interface: BrokeredConnectionControl

Is this a global transaction

Specified by:

isInGlobalTransaction in interface BrokeredConnectionControl

Returns:

true if this is a global XA transaction

See Also:

• BrokeredConnectionControl.isInGlobalTransaction()

notifyException

public void notifyException(SQLException sqle)

Notify the control class that a SQLException was thrown during a call on one of the brokered connection's methods.

Specified by:

notifyException in interface BrokeredConnectionControl

checkAutoCommit

public void checkAutoCommit(boolean autoCommit)
                     throws SQLException

Allow control over setting auto commit mode.

Specified by:

checkAutoCommit in interface BrokeredConnectionControl

Throws:

SQLException

checkHoldCursors

public int checkHoldCursors(int holdability,
 boolean downgrade)
                     throws SQLException

Are held cursors allowed.

Specified by:

checkHoldCursors in interface BrokeredConnectionControl

Parameters:

downgrade - true to downgrade the holdability, false to throw an exception.

Throws:

SQLException

checkSavepoint

public void checkSavepoint()
                    throws SQLException

Allow control over creating a Savepoint (JDBC 3.0)

Specified by:

checkSavepoint in interface BrokeredConnectionControl

Throws:

SQLException

checkRollback

public void checkRollback()
                   throws SQLException

Allow control over calling rollback.

Specified by:

checkRollback in interface BrokeredConnectionControl

Throws:

SQLException

checkCommit

public void checkCommit()
                 throws SQLException

Allow control over calling commit.

Specified by:

checkCommit in interface BrokeredConnectionControl

Throws:

SQLException

checkClose

public void checkClose()
                throws SQLException

Description copied from interface: BrokeredConnectionControl

Check if the brokered connection can be closed.

Specified by:

checkClose in interface BrokeredConnectionControl

Throws:

SQLException - if it is not allowed to call close on the brokered connection

See Also:

• BrokeredConnectionControl.checkClose()

closingConnection

public boolean closingConnection()
                          throws SQLException

Close called on BrokeredConnection. If this call returns true then getRealConnection().close() will be called. Notify listners that connection is closed. Don't close the underlying real connection as it is pooled.

Specified by:

closingConnection in interface BrokeredConnectionControl

Throws:

SQLException

wrapStatement

public Statement wrapStatement(Statement s)
                        throws SQLException

No need to wrap statements for PooledConnections.

Specified by:

wrapStatement in interface BrokeredConnectionControl

Throws:

SQLException

wrapStatement

public PreparedStatement wrapStatement(PreparedStatement ps,
 String sql,
 Object generatedKeys)
                                throws SQLException

Call the setBrokeredConnectionControl method inside the EmbedPreparedStatement class to set the BrokeredConnectionControl variable to this instance of EmbedPooledConnection This will then be used to call the onStatementErrorOccurred and onStatementClose events when the corresponding events occur on the PreparedStatement

Specified by:

wrapStatement in interface BrokeredConnectionControl

Parameters:

ps - PreparedStatment to be wrapped

sql - String

generatedKeys - Object

Returns:

returns the wrapped PreparedStatement

Throws:

SQLException

wrapStatement

public CallableStatement wrapStatement(CallableStatement cs,
 String sql)
                                throws SQLException

Call the setBrokeredConnectionControl method inside the EmbedCallableStatement class to set the BrokeredConnectionControl variable to this instance of EmbedPooledConnection This will then be used to call the onStatementErrorOccurred and onStatementClose events when the corresponding events occur on the CallableStatement

Specified by:

wrapStatement in interface BrokeredConnectionControl

Parameters:

cs - CallableStatment to be wrapped

sql - String

Returns:

returns the wrapped CallableStatement

Throws:

SQLException

toString

public String toString()

Get the string representation of this pooled connection. A pooled connection is assigned a separate id from a physical connection. When a container calls PooledConnection.toString(), it gets the string representation of this id. This is useful for developers implementing connection pools when they are trying to debug pooled connections.

Overrides:

toString in class Object

Returns:

a string representation of the uniquie id for this pooled connection.

onStatementClose

public void onStatementClose(PreparedStatement statement)

Raise the statementClosed event for all the listeners when the corresponding events occurs

Specified by:

onStatementClose in interface BrokeredConnectionControl

Parameters:

statement - the PreparedStatement that was closed

onStatementErrorOccurred

public void onStatementErrorOccurred(PreparedStatement statement,
 SQLException sqle)

Raise the statementErrorOccurred event for all the listeners when the corresponding events occurs

Specified by:

onStatementErrorOccurred in interface BrokeredConnectionControl

Parameters:

statement - the PreparedStatement in which the error occurred

sqle - the SQLException that was thrown

removeStatementEventListener

public void removeStatementEventListener(StatementEventListener listener)

Removes the specified StatementEventListener from the list of components that will be notified when the driver detects that a PreparedStatement has been closed or is invalid.

Specified by:

removeStatementEventListener in interface PooledConnection

Parameters:

listener - the component which implements the StatementEventListener interface that was previously registered with this PooledConnection object

addStatementEventListener

public void addStatementEventListener(StatementEventListener listener)

Registers a StatementEventListener with this PooledConnection object. Components that wish to be notified when PreparedStatements created by the connection are closed or are detected to be invalid may use this method to register a StatementEventListener with this PooledConnection object.

Specified by:

addStatementEventListener in interface PooledConnection

Parameters:

listener - an component which implements the StatementEventListener interface that is to be registered with this PooledConnection object

getLanguageConnectionContext

private static LanguageConnectionContext getLanguageConnectionContext(EmbedConnection conn)

Gets the LanguageConnectionContext for this connection.