[java] How to get row count in an Excel file using POI library?

Guys I'm currently using the POI 3.9 library to work with excel files. I know of the getLastRowNum() function, which returns a number of rows in an Excel file.

The only problem is getLastRowNum() returns a number with the count starting from 0.

So if an Excel file uses the first 3 rows, getLastRowNum() returns 2. If an Excel file has just 1 row, getLastRowNum() returns 0.

The problem occurs when the Excel file is completely empty. getLastRowNum() still returns 0, so I cannot determine if the Excel file has 1 row of data, or if its empty.

So how can I detect if an Excel file is empty or not ?

There are two Things you can do

use

int noOfColumns = sh.getRow(0).getPhysicalNumberOfCells();

or

int noOfColumns = sh.getRow(0).getLastCellNum();

There is a fine difference between them

1. Option 1 gives the no of columns which are actually filled with contents(If the 2nd column of 10 columns is not filled you will get 9)

2. Option 2 just gives you the index of last column. Hence done 'getLastCellNum()'

Since Sheet.getPhysicalNumberOfRows() does not count empty rows and Sheet.getLastRowNum() returns 0 both if there is one row or no rows, I use a combination of the two methods to accurately calculate the total number of rows.

int rowTotal = sheet.getLastRowNum();

if ((rowTotal > 0) || (sheet.getPhysicalNumberOfRows() > 0)) {
    rowTotal++;
}

Note: This will treat a spreadsheet with one empty row as having none but for most purposes this is probably okay.

If you do a check

if
(getLastRowNum()<1){
 res="Sheet Cannot be empty";
return
}

This will make sure you have at least one row with data except header. Below is my program which works fine. Excel file has three columns ie. ID, NAME , LASTNAME

XSSFWorkbook workbook = new XSSFWorkbook(inputstream);
        XSSFSheet sheet = workbook.getSheetAt(0);
        Row header = sheet.getRow(0);
        int n = header.getLastCellNum();
        String header1 = header.getCell(0).getStringCellValue();
        String header2 = header.getCell(1).getStringCellValue();
        String header3 = header.getCell(2).getStringCellValue();
        if (header1.equals("ID") && header2.equals("NAME")
                && header3.equals("LASTNAME")) {
            if(sheet.getLastRowNum()<1){
                System.out.println("Sheet empty");
                         return;
            }   
                        iterate over sheet to get cell values
        }else{
                          SOP("invalid format");
                          return;
                          }

To find last data row, in case you created table template in excel where it is filled partially or in between rows are empty. Logic:

int count = 0;
int emptyrow=0;
int irow=0;
while (rowIterator.hasNext()) {
    row = (Row) rowIterator.next();
    if (count != 0 && !checkIfRowIsEmpty(row)) { }
    else{
        if(count!=0 && emptyrow==irow){
            emptyrow++;
        }else{
            emptyrow=0;
            irow=0;
        }
    }
    if(emptyrow>0){
        irow++;
    }
    if(emptyrow>3){
        break;
    }
    count++;
}

Sheet.getPhysicalNumberOfRows() does not involve some empty rows. If you want to loop for all rows, do not use this to know the loop size.

getLastRowNum() return index of last row.

So if you wants to know total number of row = getLastRowNum() +1.

I hope this will work.

int rowTotal = sheet.getLastRowNum() +1;