Top Description Fields Constructors Methods

org.eclipse.persistence.internal.helper

public Class LOBValueWriter

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.

Author: King Wang
Since: TopLink/Java 5.0. July 2002.

Field Summary

Modifier and Type	Field and Description
private Accessor	accessor
private Collection<DatabaseCall>	calls
private boolean	isNativeConnectionRequired

Constructor Summary

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

Method Summary

Modifier and Type	Method and Description
public void	addCall(Call call) Add original (insert or update) call to the collection
protected void	buildAndExecuteCall(DatabaseCall dbCall, AbstractSession session)
public void	buildAndExecuteSelectCalls(AbstractSession session) Build and execute the deferred select calls.
private DatabaseCall	buildCallFromSelectStatementForLocator(SQLSelectStatement selectStatement, WriteObjectQuery writeQuery, DatabaseCall dbCall, AbstractSession session) Build the sql call from the select statement for selecting the locator
private SQLSelectStatement	buildSelectStatementForLocator(WriteObjectQuery writeQuery, DatabaseCall call, AbstractSession session) Build the select statement for selecting the locator
public void	fetchLocatorAndWriteValue(DatabaseCall dbCall, Object resultSet) Fetch the locator(s) from the result set and write LOB value to the table

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

accessor	back to summary
private Accessor accessor

calls	back to summary
private Collection<DatabaseCall> calls

isNativeConnectionRequired	back to summary
private boolean isNativeConnectionRequired

Constructor Detail

LOBValueWriter	back to summary
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

addCall	back to summary
public void addCall(Call call) Add original (insert or update) call to the collection

buildAndExecuteCall	back to summary
protected void buildAndExecuteCall(DatabaseCall dbCall, AbstractSession session)

buildAndExecuteSelectCalls	back to summary
public void buildAndExecuteSelectCalls(AbstractSession session) Build and execute the deferred select calls.

buildCallFromSelectStatementForLocator	back to summary
private DatabaseCall buildCallFromSelectStatementForLocator(SQLSelectStatement selectStatement, WriteObjectQuery writeQuery, DatabaseCall dbCall, AbstractSession session) Build the sql call from the select statement for selecting the locator

buildSelectStatementForLocator	back to summary
private SQLSelectStatement buildSelectStatementForLocator(WriteObjectQuery writeQuery, DatabaseCall call, AbstractSession session) Build the select statement for selecting the locator

fetchLocatorAndWriteValue	back to summary
public void fetchLocatorAndWriteValue(DatabaseCall dbCall, Object resultSet) throws SQLException Fetch the locator(s) from the result set and write LOB value to the table