org.apache.derby.impl.sql.execute.xplain
Class XPLAINFactory

java.lang.Object
  org.apache.derby.impl.sql.execute.xplain.XPLAINFactory

All Implemented Interfaces:

XPLAINFactoryIF

public class XPLAINFactory
extends java.lang.Object
implements XPLAINFactoryIF

This is the module implementation of the XPLAINFactoryIF. It gets lazy-loaded when needed. The factory method determines which visitor to use. The visitor is cached in this factory for later reuse.

Field Summary

private java.lang.String	currentSchema the current cached schema
private XPLAINVisitor	currentVisitor the last instance of a visitor is cached

Fields inherited from interface org.apache.derby.iapi.sql.execute.xplain.XPLAINFactoryIF

MODULE

Constructor Summary

XPLAINFactory()

Method Summary

void	freeResources() uncache the visitor and reset the factory state
XPLAINVisitor	getXPLAINVisitor() the factory method, which gets called to determine and return an appropriate XPLAINVisitor instance

Methods inherited from class java.lang.Object

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

Field Detail

currentVisitor

private XPLAINVisitor currentVisitor

the last instance of a visitor is cached

currentSchema

private java.lang.String currentSchema

the current cached schema

Constructor Detail

XPLAINFactory

public XPLAINFactory()

Method Detail

getXPLAINVisitor

public XPLAINVisitor getXPLAINVisitor()
                               throws StandardException

the factory method, which gets called to determine and return an appropriate XPLAINVisitor instance

Specified by:

getXPLAINVisitor in interface XPLAINFactoryIF

Returns:

a XPLAINVisitor to traverse the ResultSetStatistics

Throws:

StandardException

See Also:

XPLAINVisitor

freeResources

public void freeResources()

uncache the visitor and reset the factory state

Specified by:

freeResources in interface XPLAINFactoryIF