Is there a way to hide excel formula using Apache POI - excel

Question

I want to populate column B value on basis of value selected in Drop down of column A. Working fine, with the help of VLOOKUP formula in all cells of column B. But now I want to hide the formula for column B cells, in order to avoid the formula alteration by user(even by mistake).
But formula should work as expected even after hiding it.
Is there any way to achieve it using Apache POI. Or Is there any other way to achieve auto population on basis of selection in drop down using Apache POI.
Thankyou in advance.

Answer 1

Hiding formulas is part of the cell style in Excel. So the simplest answer would be to use CellStyle.setHidden(true).
But that will only hide the formula but not prevent the formula alteration by user. This is what sheet protection is for. So you would need a combination of the both.
Following complete example shows that. Fomulas in C2:C4 are hidden and protected.
import java.io.FileOutputStream;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
public class CreateExcelDefaultColumnStyleNotLockedAndLockedHideFormulas {
public static void main(String[] args) throws Exception {
Workbook workbook = new XSSFWorkbook(); String filePath = "./CreateExcelDefaultColumnStyleNotLockedAndLockedHideFormulas.xlsx";
//Workbook workbook = new HSSFWorkbook(); String filePath = "./CreateExcelDefaultColumnStyleNotLockedAndLockedHideFormulas.xls";
CellStyle lockedHideFormulas = workbook.createCellStyle();
lockedHideFormulas.setLocked(true);
lockedHideFormulas.setHidden(true);
CellStyle notLocked = workbook.createCellStyle();
notLocked.setLocked(false);
Sheet sheet = workbook.createSheet();
Row row = sheet.createRow(0);
Cell cell = null;
for (int c = 0; c < 3; c++) {
cell = row.createCell(c);
cell.setCellValue("Col " + (c+1));
}
for (int r = 1; r < 4; r++) {
row = sheet.createRow(r);
for (int c = 0; c < 2; c++) {
cell = row.createCell(c);
cell.setCellValue(r * (c+1));
cell.setCellStyle(notLocked);
}
cell = row.createCell(2);
cell.setCellFormula("A" + (r+1) + "*B" + (r+1));
cell.setCellStyle(lockedHideFormulas);
}
sheet.setDefaultColumnStyle(0, notLocked);
sheet.setDefaultColumnStyle(1, notLocked);
sheet.setDefaultColumnStyle(2, notLocked);
sheet.protectSheet("");
FileOutputStream out = new FileOutputStream(filePath);
workbook.write(out);
out.close();
workbook.close();
}
}