poi has a implicitly max row number - apache-poi

Question

I used poi 3.12 to create excel, and found a phenomenon, that is explicitly created 30000 rows, but open the generated excel, only have 27239 rows, and there is no error output. So it seems poi have set a default max row number--27239. But I tried track source code, cannot find some variable like max rows. The code is
InputStream is = new FileInputStream(srcFile);
POIFSFileSystem pOIFSFileSystem=new POIFSFileSystem(is);
HSSFWorkbook srcWorkbook = new HSSFWorkbook(pOIFSFileSystem);
buildBusiData(srcWorkbook);
FileOutputStream fileOutputStream = new FileOutputStream(desFile);
srcWorkbook.write(fileOutputStream);
fileOutputStream.flush();
fileOutputStream.close();
So how is this?

Answer 1

I have found the reason, that is the source file(template) only have 27239 rows
#source file
cat coupon_code_box.csv | wc -l
27240
#
head coupon_code_box.csv -n 3
table header here
" "," "," "," "," "," "," "," "," "
" "," "," "," "," "," "," "," "," "
and in my code does not create new row explicitly, so if row number greater than 27239, it'll ignore it.
Row row = sheet.getRow(rowIndex);
if(row!=null){
Cell cell = row.getCell(celIndex);
cell.setCellValue(fillVal);
}
Now my solution is
Row row = sheet.getRow(rowIndex);
if(row==null){
row=sheet.createRow(rowIndex); //explicitly create one new row
}
if(row!=null){
Cell cell = row.getCell(celIndex);
if(cell==null)
cell = row.createCell(celIndex); //explicitly create one new cell
cell.setCellValue(fillVal);
}