How to set formulas in cells using Apache POI?

Question

I am currently using Apache POI for Java to set formulas in cells.

But after I run the program and open the Excel file that I created and processed, the cells with t

Answer 1

The below code worked fine for me, hope this could be useful to someone.

cell.setCellType(Cell.CELL_TYPE_FORMULA);
cell.setCellFormula("SUM(C70:C76)");

Answer 2

Here is one suggested way:

Workbook workbook1 = new SXSSFWorkbook(-1);
Sheet newSheet = workbook1.createSheet("Valuations");
Row newRow = newSheet.createRow(i-1);
newRow.createCell(L++).setCellFormula("AVERAGE(" + "E" + i + ":" + "G" + i + ")");

Where E and G are the columns like A1,B1,C1....E1...G1
and i represent a number in the above Column.

L++ is simply an incremental counter.

Answer 3

You could use this to evaluate the formulas in the workbook:

        // Evaluate all formulas in the sheet, to update their value
    FormulaEvaluator formulaEvaluator = workbook.getCreationHelper().createFormulaEvaluator();
    formulaEvaluator.evaluateAll();

Answer 4

Cell Constants are deprecated and will be removed from version 4.0 instead of Cell Use

CellType.FORMULA

String formula= "SUM(B4:B20)";
cell.setCellType(CellType.FORMULA);
cell.setCellFormula(formula);

Answer 5

Apache POI does not support user-defined functions.

From the documentation:

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!

Answer 6

The HSSFCell object has methods .setCellType and .setCellFormula which you need to call like this:

// "cell" object previously created or looked up
String strFormula= "SUM(A1:A10)";
cell.setCellType(HSSFCell.CELL_TYPE_FORMULA);
cell.setCellFormula(strFormula);