Package org.apache.derby.impl.drda

Class PiggyBackedSessionData

java.lang.Object

org.apache.derby.impl.drda.PiggyBackedSessionData

class PiggyBackedSessionData
extends java.lang.Object

Tracks the most recently piggy-backed session attributes, and provides methods to determine if they have been modified and need to be re-sent to the client.

Field Summary

Fields

Modifier and Type	Field	Description
private EngineConnection	conn_
private int	iso_
private boolean	isoMod_
private java.lang.String	schema_
private boolean	schemaMod_

Constructor Summary

Constructors

Modifier	Constructor	Description
private	PiggyBackedSessionData(EngineConnection conn)	Constructs a new instance with an associated EngineConnection.

Method Summary

Modifier and Type	Method	Description
static PiggyBackedSessionData	getInstance(PiggyBackedSessionData existing, EngineConnection conn, boolean createOnDemand)	Get a reference (handle) to the PiggyBackedSessionData object.
int	getIso()
java.lang.String	getSchema()
boolean	isIsoModified()
boolean	isModified()
boolean	isSchemaModified()
void	refresh()	Refresh with the latest session attribute values from the connection.
void	setUnmodified()	Clear the modified status.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

iso_

private int iso_

isoMod_

private boolean isoMod_

schema_

private java.lang.String schema_

schemaMod_

private boolean schemaMod_

conn_

private final EngineConnection conn_

Constructor Detail

PiggyBackedSessionData

private PiggyBackedSessionData(EngineConnection conn)

Constructs a new instance with an associated EngineConnection. A newly constructed instance is invalid. refresh() must be called before the xModified() methods can be used.

Parameters:

conn - the connection to obtain data from

Method Detail

getInstance

public static PiggyBackedSessionData getInstance(PiggyBackedSessionData existing,
                                                 EngineConnection conn,
                                                 boolean createOnDemand)
                                          throws java.sql.SQLException

Get a reference (handle) to the PiggyBackedSessionData object. Null will be returned either if the conn argument is not valid, or if the createOnDemand argument is false and the existing argument is null.

Parameters:

existing - the PBSD object from the previous piggybacking or null if none has yet taken place

conn - the current EngineConnection

createOnDemand - if true; create the instance when needed

Returns:

a reference to the PBSD object or null

Throws:

java.sql.SQLException

refresh

public void refresh()
             throws java.sql.SQLException

Refresh with the latest session attribute values from the connection. Any changes will be reflected in the corresponding xModified() methods, until setUnmodified() is called.

Throws:

java.sql.SQLException

setUnmodified

public void setUnmodified()

Clear the modified status. Called after session attributes have been sent to the client so that the xModified methods will return false.

isIsoModified

public boolean isIsoModified()

Returns:

true if the isolation level was modified by the last call to fetchLatest

isSchemaModified

public boolean isSchemaModified()

Returns:

true if the current schema name was modified by the last call to fetchLatest

isModified

public boolean isModified()

Returns:

true if any piggy-backed session attribute was modified by the last call to fetchLatest

getIso

public int getIso()

Returns:

the saved jdbc isolation level

getSchema

public java.lang.String getSchema()

Returns:

the saved schema name

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object