Class ForkedEvaluator
- java.lang.Object
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- org.apache.poi.ss.formula.eval.forked.ForkedEvaluator
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public final class ForkedEvaluator extends java.lang.Object
An alternative workbook evaluator that saves memory in situations where a single workbook is concurrently and independently evaluated many times. With standard formula evaluation, around 90% of memory consumption is due to loading of theHSSFWorkbook
orXSSFWorkbook
. This class enables a 'master workbook' to be loaded just once and shared between many evaluation clients. Each evaluation client creates its ownForkedEvaluator
and can set cell values that will be used for local evaluations (and don't disturb evaluations on other evaluators).
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description void
copyUpdatedCells(Workbook workbook)
Copies the values of all updated cells (modified by calls toupdateCell(String, int, int, ValueEval)
) to the supplied workbook.
Typically, the supplied workbook is a writable copy of the 'master workbook', but at the very least it must contain sheets with the same names.static ForkedEvaluator
create(Workbook wb, IStabilityClassifier stabilityClassifier, UDFFinder udfFinder)
ValueEval
evaluate(java.lang.String sheetName, int rowIndex, int columnIndex)
If cell contains a formula, the formula is evaluated and returned, else the CellValue simply copies the appropriate cell value from the cell and also its cell type.static void
setupEnvironment(java.lang.String[] workbookNames, ForkedEvaluator[] evaluators)
Coordinates several formula evaluators together so that formulas that involve external references can be evaluated.void
updateCell(java.lang.String sheetName, int rowIndex, int columnIndex, ValueEval value)
Sets the specified cell to the supplied value
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Method Detail
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create
public static ForkedEvaluator create(Workbook wb, IStabilityClassifier stabilityClassifier, UDFFinder udfFinder)
- Parameters:
udfFinder
- passnull
for default (AnalysisToolPak only)
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updateCell
public void updateCell(java.lang.String sheetName, int rowIndex, int columnIndex, ValueEval value)
Sets the specified cell to the supplied value- Parameters:
sheetName
- the name of the sheet containing the cellrowIndex
- zero basedcolumnIndex
- zero based
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copyUpdatedCells
public void copyUpdatedCells(Workbook workbook)
Copies the values of all updated cells (modified by calls toupdateCell(String, int, int, ValueEval)
) to the supplied workbook.
Typically, the supplied workbook is a writable copy of the 'master workbook', but at the very least it must contain sheets with the same names.
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evaluate
public ValueEval evaluate(java.lang.String sheetName, int rowIndex, int columnIndex)
If cell contains a formula, the formula is evaluated and returned, else the CellValue simply copies the appropriate cell value from the cell and also its cell type. This method should be preferred over evaluateInCell() when the call should not modify the contents of the original cell.- Parameters:
sheetName
- the name of the sheet containing the cellrowIndex
- zero basedcolumnIndex
- zero based- Returns:
null
if the supplied cell isnull
or blank
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setupEnvironment
public static void setupEnvironment(java.lang.String[] workbookNames, ForkedEvaluator[] evaluators)
Coordinates several formula evaluators together so that formulas that involve external references can be evaluated.- Parameters:
workbookNames
- the simple file names used to identify the workbooks in formulas with external links (for example "MyData.xls" as used in a formula "[MyData.xls]Sheet1!A1")evaluators
- all evaluators for the full set of workbooks required by the formulas.
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