diff --git a/src/documentation/content/xdocs/spreadsheet/eval.xml b/src/documentation/content/xdocs/spreadsheet/eval.xml index a0d7ae4a7..7f31017ed 100644 --- a/src/documentation/content/xdocs/spreadsheet/eval.xml +++ b/src/documentation/content/xdocs/spreadsheet/eval.xml @@ -48,57 +48,59 @@ functions in Excel. The framework however makes is easy to add implementation of new functions. See the Formula evaluation development guide for details.

+

Both HSSFWorkbook and XSSFWorkbook are supported, so you can + evaluate formulas on both .xls and .xlsx files.

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!

User API How-TO -

The following code demonstrates how to use the HSSFFormulaEvaluator +

The following code demonstrates how to use the FormulaEvaluator in the context of other POI excel reading code.

-

There are several ways in which you can use the HSSFFormulaEvalutator API.

+

There are several ways in which you can use the FormulaEvalutator API.

-
Using HSSFFormulaEvaluator.<strong>evaluate</strong>(HSSFCell cell) +
Using FormulaEvaluator.<strong>evaluate</strong>(Cell cell)

This evaluates a given cell, and returns the new value, without affecting the cell

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; }

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()) {

-
Using HSSFFormulaEvaluator.<strong>evaluateFormulaCell</strong>(HSSFCell cell) -

evaluateFormulaCell(HSSFCell cell) +

Using FormulaEvaluator.<strong>evaluateFormulaCell</strong>(Cell cell) +

evaluateFormulaCell(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

The return of the function is the type of the - formula result, such as HSSFCell.CELL_TYPE_BOOLEAN

+ formula result, such as Cell.CELL_TYPE_BOOLEAN

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 (evaluator.evaluateFormulaCell(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) {
-
Using HSSFFormulaEvaluator.<strong>evaluateInCell</strong>(HSSFCell cell) -

evaluateInCell(HSSFCell cell) will check to +

Using FormulaEvaluator.<strong>evaluateInCell</strong>(Cell cell) +

evaluateInCell(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.

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 (evaluator.evaluateInCell(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) {
Re-calculating all formulas in a Workbook 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"));
Performance Notes
    -
  • Generally you should have to create only one HSSFFormulaEvaluator +
  • 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.
    • -
  • Also note that HSSFFormulaEvaluator maintains a reference to +
  • 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).
  • 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.