Package org.eclipse.persistence.internal.helper

Class LOBValueWriter

java.lang.Object

org.eclipse.persistence.internal.helper.LOBValueWriter

public class LOBValueWriter
extends Object

INTERNAL:

Purpose:LOBValueWriter is used to write a large size of object into an Oracle CLOB/BLOB column through Oracle LOB Locator. It's a work-around object for the well-known 4k write limits on an Oracle thin driver.

Responsibilities:

• Build the Oracle empty lob method call string for the insert call.
• Build the minimal SELECT call to retrieve the locator.
• Write the lob value through the locator.
• Resolve the multiple table INSERT/SELECT orders.
• Resolve the nested unit of work commit issue.

Since:

TopLink/Java 5.0. July 2002.

Author:

King Wang

Constructor Summary

Constructors

Constructor	Description
LOBValueWriter(Accessor accessor)	This is the default constructor for the class.

Method Summary

Modifier and Type	Method	Description
void	addCall(Call call)	Add original (insert or update) call to the collection
protected void	buildAndExecuteCall(DatabaseCall dbCall, AbstractSession session)
void	buildAndExecuteSelectCalls(AbstractSession session)	Build and execute the deferred select calls.
void	fetchLocatorAndWriteValue(DatabaseCall dbCall, Object resultSet)	Fetch the locator(s) from the result set and write LOB value to the table

Methods inherited from class java.lang.Object

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

Constructor Detail

LOBValueWriter

public LOBValueWriter(Accessor accessor)

This is the default constructor for the class. Bug 2804663 - Each DatabaseAccessor will now hold on to its own instance of this class, hence a singleton pattern is not applicable.

Method Detail

buildAndExecuteCall

protected void buildAndExecuteCall(DatabaseCall dbCall,
                                   AbstractSession session)

fetchLocatorAndWriteValue

public void fetchLocatorAndWriteValue(DatabaseCall dbCall,
                                      Object resultSet)
                               throws SQLException

Fetch the locator(s) from the result set and write LOB value to the table

Throws:

SQLException

addCall

public void addCall(Call call)

Add original (insert or update) call to the collection

buildAndExecuteSelectCalls

public void buildAndExecuteSelectCalls(AbstractSession session)

Build and execute the deferred select calls.