mirror of https://github.com/apache/poi.git
Update formula eval docs for xssf support
git-svn-id: https://svn.apache.org/repos/asf/poi/branches/ooxml@642637 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Nick Burch
parent
0cd7ba4ad2
commit
83ee6d319c
|
|
@ -48,57 +48,59 @@
|
|||
functions in Excel. The framework however makes is easy to add
|
||||
implementation of new functions. See the <link href="eval-devguide.html"> Formula
|
||||
evaluation development guide</link> for details. </p>
|
||||
<p> Both HSSFWorkbook and XSSFWorkbook are supported, so you can
|
||||
evaluate formulas on both .xls and .xlsx files.</p>
|
||||
<p> Note that user-defined functions are not supported, and is not likely to done
|
||||
any time soon... at least, not till there is a VB implementation in Java!
|
||||
</p>
|
||||
</section>
|
||||
<section><title>User API How-TO</title>
|
||||
<p>The following code demonstrates how to use the HSSFFormulaEvaluator
|
||||
<p>The following code demonstrates how to use the FormulaEvaluator
|
||||
in the context of other POI excel reading code.
|
||||
</p>
|
||||
<p>There are several ways in which you can use the HSSFFormulaEvalutator API.</p>
|
||||
<p>There are several ways in which you can use the FormulaEvalutator API.</p>
|
||||
|
||||
<anchor id="Evaluate"/>
|
||||
<section><title>Using HSSFFormulaEvaluator.<strong>evaluate</strong>(HSSFCell cell)</title>
|
||||
<section><title>Using FormulaEvaluator.<strong>evaluate</strong>(Cell cell)</title>
|
||||
<p>This evaluates a given cell, and returns the new value,
|
||||
without affecting the cell</p>
|
||||
<source>
|
||||
FileInputStream fis = new FileInputStream("c:/temp/test.xls");
|
||||
HSSFWorkbook wb = new HSSFWorkbook(fis);
|
||||
HSSFSheet sheet = wb.getSheetAt(0);
|
||||
HSSFFormulaEvaluator evaluator = new HSSFFormulaEvaluator(sheet, wb);
|
||||
Workbook wb = new HSSFWorkbook(fis);
|
||||
Sheet sheet = wb.getSheetAt(0);
|
||||
FormulaEvaluator evaluator = new FormulaEvaluator(sheet, wb);
|
||||
|
||||
// suppose your formula is in B3
|
||||
CellReference cellReference = new CellReference("B3");
|
||||
HSSFRow row = sheet.getRow(cellReference.getRow());
|
||||
HSSFCell cell = row.getCell(cellReference.getCol());
|
||||
Row row = sheet.getRow(cellReference.getRow());
|
||||
Cell cell = row.getCell(cellReference.getCol());
|
||||
|
||||
evaluator.setCurrentRow(row);
|
||||
HSSFFormulaEvaluator.CellValue cellValue = evaluator.evaluate(cell);
|
||||
FormulaEvaluator.CellValue cellValue = evaluator.evaluate(cell);
|
||||
|
||||
switch (cellValue.getCellType()) {
|
||||
case HSSFCell.CELL_TYPE_BOOLEAN:
|
||||
case Cell.CELL_TYPE_BOOLEAN:
|
||||
System.out.println(cellValue.getBooleanValue());
|
||||
break;
|
||||
case HSSFCell.CELL_TYPE_NUMERIC:
|
||||
case Cell.CELL_TYPE_NUMERIC:
|
||||
System.out.println(cellValue.getNumberValue());
|
||||
break;
|
||||
case HSSFCell.CELL_TYPE_STRING:
|
||||
case Cell.CELL_TYPE_STRING:
|
||||
System.out.println(cellValue.getStringValue());
|
||||
break;
|
||||
case HSSFCell.CELL_TYPE_BLANK:
|
||||
case Cell.CELL_TYPE_BLANK:
|
||||
break;
|
||||
case HSSFCell.CELL_TYPE_ERROR:
|
||||
case Cell.CELL_TYPE_ERROR:
|
||||
break;
|
||||
|
||||
// CELL_TYPE_FORMULA will never happen
|
||||
case HSSFCell.CELL_TYPE_FORMULA:
|
||||
case Cell.CELL_TYPE_FORMULA:
|
||||
break;
|
||||
}
|
||||
</source>
|
||||
<p>Thus using the retrieved value (of type
|
||||
HSSFFormulaEvaluator.CellValue - a nested class) returned
|
||||
by HSSFFormulaEvaluator is similar to using a HSSFCell object
|
||||
FormulaEvaluator.CellValue - a nested class) returned
|
||||
by FormulaEvaluator is similar to using a Cell object
|
||||
containing the value of the formula evaluation. CellValue is
|
||||
a simple value object and does not maintain reference
|
||||
to the original cell.
|
||||
|
|
@ -106,46 +108,46 @@ switch (cellValue.getCellType()) {
|
|||
</section>
|
||||
|
||||
<anchor id="EvaluateFormulaCell"/>
|
||||
<section><title>Using HSSFFormulaEvaluator.<strong>evaluateFormulaCell</strong>(HSSFCell cell)</title>
|
||||
<p><strong>evaluateFormulaCell</strong>(HSSFCell cell)
|
||||
<section><title>Using FormulaEvaluator.<strong>evaluateFormulaCell</strong>(Cell cell)</title>
|
||||
<p><strong>evaluateFormulaCell</strong>(Cell cell)
|
||||
will check to see if the supplied cell is a formula cell.
|
||||
If it isn't, then no changes will be made to it. If it is,
|
||||
then the formula is evaluated. The value for the formula
|
||||
is saved alongside it, to be displayed in excel. The
|
||||
formula remains in the cell, just with a new value</p>
|
||||
<p>The return of the function is the type of the
|
||||
formula result, such as HSSFCell.CELL_TYPE_BOOLEAN</p>
|
||||
formula result, such as Cell.CELL_TYPE_BOOLEAN</p>
|
||||
<source>
|
||||
FileInputStream fis = new FileInputStream("/somepath/test.xls");
|
||||
HSSFWorkbook wb = new HSSFWorkbook(fis);
|
||||
HSSFSheet sheet = wb.getSheetAt(0);
|
||||
HSSFFormulaEvaluator evaluator = new HSSFFormulaEvaluator(sheet, wb);
|
||||
Workbook wb = new HSSFWorkbook(fis);
|
||||
Sheet sheet = wb.getSheetAt(0);
|
||||
FormulaEvaluator evaluator = new FormulaEvaluator(sheet, wb);
|
||||
|
||||
// suppose your formula is in B3
|
||||
CellReference cellReference = new CellReference("B3");
|
||||
HSSFRow row = sheet.getRow(cellReference.getRow());
|
||||
HSSFCell cell = row.getCell(cellReference.getCol());
|
||||
Row row = sheet.getRow(cellReference.getRow());
|
||||
Cell cell = row.getCell(cellReference.getCol());
|
||||
evaluator.setCurrentRow(row);
|
||||
|
||||
if (cell!=null) {
|
||||
switch (<strong>evaluator.evaluateFormulaCell</strong>(cell)) {
|
||||
case HSSFCell.CELL_TYPE_BOOLEAN:
|
||||
case Cell.CELL_TYPE_BOOLEAN:
|
||||
System.out.println(cell.getBooleanCellValue());
|
||||
break;
|
||||
case HSSFCell.CELL_TYPE_NUMERIC:
|
||||
case Cell.CELL_TYPE_NUMERIC:
|
||||
System.out.println(cell.getNumberCellValue());
|
||||
break;
|
||||
case HSSFCell.CELL_TYPE_STRING:
|
||||
case Cell.CELL_TYPE_STRING:
|
||||
System.out.println(cell.getStringCellValue());
|
||||
break;
|
||||
case HSSFCell.CELL_TYPE_BLANK:
|
||||
case Cell.CELL_TYPE_BLANK:
|
||||
break;
|
||||
case HSSFCell.CELL_TYPE_ERROR:
|
||||
case Cell.CELL_TYPE_ERROR:
|
||||
System.out.println(cell.getErrorCellValue());
|
||||
break;
|
||||
|
||||
// CELL_TYPE_FORMULA will never occur
|
||||
case HSSFCell.CELL_TYPE_FORMULA:
|
||||
case Cell.CELL_TYPE_FORMULA:
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
|
@ -153,43 +155,43 @@ if (cell!=null) {
|
|||
</section>
|
||||
|
||||
<anchor id="EvaluateInCell"/>
|
||||
<section><title>Using HSSFFormulaEvaluator.<strong>evaluateInCell</strong>(HSSFCell cell)</title>
|
||||
<p><strong>evaluateInCell</strong>(HSSFCell cell) will check to
|
||||
<section><title>Using FormulaEvaluator.<strong>evaluateInCell</strong>(Cell cell)</title>
|
||||
<p><strong>evaluateInCell</strong>(Cell cell) will check to
|
||||
see if the supplied cell is a formula cell. If it isn't,
|
||||
then no changes will be made to it. If it is, then the
|
||||
formula is evaluated, and the new value saved into the cell,
|
||||
in place of the old formula.</p>
|
||||
<source>
|
||||
FileInputStream fis = new FileInputStream("/somepath/test.xls");
|
||||
HSSFWorkbook wb = new HSSFWorkbook(fis);
|
||||
HSSFSheet sheet = wb.getSheetAt(0);
|
||||
HSSFFormulaEvaluator evaluator = new HSSFFormulaEvaluator(sheet, wb);
|
||||
Workbook wb = new HSSFWorkbook(fis);
|
||||
Sheet sheet = wb.getSheetAt(0);
|
||||
FormulaEvaluator evaluator = new FormulaEvaluator(sheet, wb);
|
||||
|
||||
// suppose your formula is in B3
|
||||
CellReference cellReference = new CellReference("B3");
|
||||
HSSFRow row = sheet.getRow(cellReference.getRow());
|
||||
HSSFCell cell = row.getCell(cellReference.getCol());
|
||||
Row row = sheet.getRow(cellReference.getRow());
|
||||
Cell cell = row.getCell(cellReference.getCol());
|
||||
evaluator.setCurrentRow(row);
|
||||
|
||||
if (cell!=null) {
|
||||
switch (<strong>evaluator.evaluateInCell</strong>(cell).getCellType()) {
|
||||
case HSSFCell.CELL_TYPE_BOOLEAN:
|
||||
case Cell.CELL_TYPE_BOOLEAN:
|
||||
System.out.println(cell.getBooleanCellValue());
|
||||
break;
|
||||
case HSSFCell.CELL_TYPE_NUMERIC:
|
||||
case Cell.CELL_TYPE_NUMERIC:
|
||||
System.out.println(cell.getNumberCellValue());
|
||||
break;
|
||||
case HSSFCell.CELL_TYPE_STRING:
|
||||
case Cell.CELL_TYPE_STRING:
|
||||
System.out.println(cell.getStringCellValue());
|
||||
break;
|
||||
case HSSFCell.CELL_TYPE_BLANK:
|
||||
case Cell.CELL_TYPE_BLANK:
|
||||
break;
|
||||
case HSSFCell.CELL_TYPE_ERROR:
|
||||
case Cell.CELL_TYPE_ERROR:
|
||||
System.out.println(cell.getErrorCellValue());
|
||||
break;
|
||||
|
||||
// CELL_TYPE_FORMULA will never occur
|
||||
case HSSFCell.CELL_TYPE_FORMULA:
|
||||
case Cell.CELL_TYPE_FORMULA:
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
|
@ -200,18 +202,18 @@ if (cell!=null) {
|
|||
<section><title>Re-calculating all formulas in a Workbook</title>
|
||||
<source>
|
||||
FileInputStream fis = new FileInputStream("/somepath/test.xls");
|
||||
HSSFWorkbook wb = new HSSFWorkbook(fis);
|
||||
Workbook wb = new HSSFWorkbook(fis);
|
||||
for(int sheetNum = 0; sheetNum < wb.getNumberOfSheets(); sheetNum++) {
|
||||
HSSFSheet sheet = wb.getSheetAt(sheetNum);
|
||||
HSSFFormulaEvaluator evaluator = new HSSFFormulaEvaluator(sheet, wb);
|
||||
Sheet sheet = wb.getSheetAt(sheetNum);
|
||||
FormulaEvaluator evaluator = new FormulaEvaluator(sheet, wb);
|
||||
|
||||
for(Iterator rit = sheet.rowIterator(); rit.hasNext();) {
|
||||
HSSFRow r = (HSSFRow)rit.next();
|
||||
Row r = (Row)rit.next();
|
||||
evaluator.setCurrentRow(r);
|
||||
|
||||
for(Iterator cit = r.cellIterator(); cit.hasNext();) {
|
||||
HSSFCell c = (HSSFCell)cit.next();
|
||||
if(c.getCellType() == HSSFCell.CELL_TYPE_FORMULA) {
|
||||
Cell c = (Cell)cit.next();
|
||||
if(c.getCellType() == Cell.CELL_TYPE_FORMULA) {
|
||||
evaluator.evaluateFormulaCell(c);
|
||||
}
|
||||
}
|
||||
|
|
@ -225,22 +227,22 @@ wb.write(new FileOutputStream("/somepath/changed.xls"));
|
|||
<anchor id="Performance"/>
|
||||
<section><title>Performance Notes</title>
|
||||
<ul>
|
||||
<li>Generally you should have to create only one HSSFFormulaEvaluator
|
||||
<li>Generally you should have to create only one FormulaEvaluator
|
||||
instance per sheet, but there really is no overhead in creating
|
||||
multiple HSSFFormulaEvaluators per sheet other than that of the
|
||||
HSSFFormulaEvaluator object creation.
|
||||
multiple FormulaEvaluators per sheet other than that of the
|
||||
FormulaEvaluator object creation.
|
||||
</li>
|
||||
<li>Also note that HSSFFormulaEvaluator maintains a reference to
|
||||
<li>Also note that FormulaEvaluator maintains a reference to
|
||||
the sheet and workbook, so ensure that the evaluator instance
|
||||
is available for garbage collection when you are done with it
|
||||
(in other words don't maintain long lived reference to
|
||||
HSSFFormulaEvaluator if you don't really need to - unless
|
||||
FormulaEvaluator if you don't really need to - unless
|
||||
all references to the sheet and workbook are removed, these
|
||||
don't get garbage collected and continue to occupy potentially
|
||||
large amounts of memory).
|
||||
</li>
|
||||
<li>CellValue instances however do not maintain reference to the
|
||||
HSSFCell or the sheet or workbook, so these can be long-lived
|
||||
Cell or the sheet or workbook, so these can be long-lived
|
||||
objects without any adverse effect on performance.
|
||||
</li>
|
||||
</ul>
|
||||
|
|
|
|||
Loading…
Reference in New Issue