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

问题

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 ?

回答1:

Try Sheet.getPhysicalNumberOfRows()

回答2:

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;
                          }

回答3:

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()'

回答4:

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.

回答5:

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++;
}

来源：https://stackoverflow.com/questions/16234486/how-to-get-row-count-in-an-excel-file-using-poi-library