Package org.openl.rules.lang.xls.load

Class UnloadableLazyWorkbookLoader

java.lang.Object

org.openl.rules.lang.xls.load.UnloadableLazyWorkbookLoader

All Implemented Interfaces:

WorkbookLoader

public class UnloadableLazyWorkbookLoader
extends Object
implements WorkbookLoader

Provides lazy loading access to the workbook. When getWorkbook() first time is called, it is loaded from file system and then is cached using WeakReference. If that workbook is used nowhere, it can at a certain moment be garbage collected, and after that if getWorkbook() is called, the workbook will be loaded again. If you want to prevent garbage collecting loaded Workbook instance, invoke setCanUnload(false).

Constructor Summary

Constructors

Constructor	Description
UnloadableLazyWorkbookLoader(IOpenSourceCodeModule fileSource)

Method Summary

Modifier and Type	Method	Description
int	getNumberOfSheets()	Get number of sheets in current workbook.
SheetLoader	getSheetLoader(int sheetIndex)	Get the sheet accessor
SpreadsheetConstants	getSpreadsheetConstants()
org.apache.poi.ss.usermodel.Workbook	getWorkbook()	Get the workbook.
boolean	isCanUnload()	If true - the workbook can (but mustn't) be unloaded (for example if there is no enough memory).
protected org.apache.poi.ss.usermodel.Workbook	loadWorkbook()
void	setCanUnload(boolean canUnload)	Set the flag that this workbook can or cannot be unloaded.

Methods inherited from class java.lang.Object

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

Constructor Detail

UnloadableLazyWorkbookLoader

public UnloadableLazyWorkbookLoader(IOpenSourceCodeModule fileSource)

Method Detail

getWorkbook

public org.apache.poi.ss.usermodel.Workbook getWorkbook()

Get the workbook. Depending on isCanUnload() state, when this method is repeatedly called, it can (but mustn't) return different instances of workbook java object.

Specified by:

getWorkbook in interface WorkbookLoader

Returns:

loaded workbook

See Also:

isCanUnload()

loadWorkbook

protected org.apache.poi.ss.usermodel.Workbook loadWorkbook()

getSheetLoader

public SheetLoader getSheetLoader(int sheetIndex)

Get the sheet accessor

Specified by:

getSheetLoader in interface WorkbookLoader

Parameters:

sheetIndex - the sheet index in the workbook

Returns:

object that provides access to the specified sheet of current workbook

isCanUnload

public boolean isCanUnload()

If true - the workbook can (but mustn't) be unloaded (for example if there is no enough memory). In this case when the WorkbookLoader.getWorkbook() is repeatedly called, it can (but mustn't) return different instances of workbook java object.

If false - the workbook is not unloaded and WorkbookLoader.getWorkbook() always returns the same Workbook instance.

Specified by:

isCanUnload in interface WorkbookLoader

Returns:

the flag that this workbook can or cannot be unloaded.

See Also:

WorkbookLoader.setCanUnload(boolean)

setCanUnload

public void setCanUnload(boolean canUnload)

Set the flag that this workbook can or cannot be unloaded. If workbook cannot be unloaded (for example when we edit the workbook) internal implementation should always keep strong reference to workbook and WorkbookLoader.getWorkbook() always returns the same Workbook instance.

Specified by:

setCanUnload in interface WorkbookLoader

Parameters:

canUnload - the flag that this workbook can or cannot be unloaded

See Also:

WorkbookLoader.isCanUnload()

getNumberOfSheets

public int getNumberOfSheets()

Get number of sheets in current workbook.

Specified by:

getNumberOfSheets in interface WorkbookLoader

Returns:

the number of sheets in current workbook

getSpreadsheetConstants

public SpreadsheetConstants getSpreadsheetConstants()

Specified by:

getSpreadsheetConstants in interface WorkbookLoader