POI - SXSSFWorkbook - Excel found unreadable content

Question

I have an existing workbook that acts as template. I tried to update a cell value in an existing row, meaning the adjacent cell has a value. The problem is that after the file is created and I open it, I get the following error: "Excel found unreadable content in...."

I assume the reason is SXSSFWorkbook only handles writing and if a row exists it cant update the contents of the row, which would entail reading and then writing - is this correct or am I experiencing a bug?

Thanks

Answer 1

Another issue is that if you're using addMergedRegion, the CellRangeAddress values for rows and columns have to be in ascending numerical order:

// Note that rows and columns for CellRangeAddress constructor have to be in ascending order
// The commented out line below will generate an error when opening the sheet:
// sheet.addMergedRegion(new CellRangeAddress(lastRow, lastRow-(rowsTobeCreated-1), 0, 0));
// In order this call works:
sheet.addMergedRegion(new CellRangeAddress(lastRow-(rowsTobeCreated-1), lastRow, 0, 0));

Answer 2

In case anyone else has this problem, check to make sure the length of your SheetName is not too long. I was getting this error when setting the workbook sheet name longer than around 30 characters.

  XSSFWorkbook wb = new XSSFWorkbook();
  XSSFSheet sheet = wb.createSheet();
  wb.setSheetName(0, "Supporting Documentation"); // make sure this is not too long