apache poi - Count number of rows in a column of Excel sheet(Java code provided)

Question

In reference to my previous question How to calculate number of rows in a column of Excel document using Java i was able to calculate the total number of columns in the given sheet. Now half of the work is yet to be done as i want to calculate the number of rows in a particular column. Possible solution could be using 2d array and storing column index and the total rows or using map, etc. How i can achieve this? Java code is provided here. I'm getting right count(column count) for my demo file. Please modify/suggest changes as required.

(edit): i've used hasp map to calculate store column index as key and row count as value, but it wasnt working, may be the applied logic was wrong. Well, if i want to accomplish this by using Hash Map, how i can store number of rows in a particular column(while iterating) as a value

Java Code:

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;

import org.apache.poi.ss.formula.functions.Column;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ExcelRead {
    static int colrange=1000;
    public static void main(String[] args) {
        HashMap hm=new HashMap();
        int count=0;
    try {
        FileInputStream file = new FileInputStream(new File("C:/Users/vinayakp/Desktop/Demo2.xlsx"));
        XSSFWorkbook workbook = new XSSFWorkbook(file);
        XSSFSheet sheet = workbook.getSheetAt(0);
        Iterator<Row> rowIterator = sheet.iterator();
        while(rowIterator.hasNext()) {
            Row row = rowIterator.next();
            Iterator<Cell> cellIterator = row.cellIterator();
            while(cellIterator.hasNext()) {
                Cell cell = cellIterator.next();
                switch(cell.getCellType()) {
                    case Cell.CELL_TYPE_BOOLEAN:
                        System.out.print(cell.getBooleanCellValue() + "");
                        break;
                    case Cell.CELL_TYPE_NUMERIC:
                        System.out.print(cell.getNumericCellValue() + "");
                        break;
                    case Cell.CELL_TYPE_STRING:
                        System.out.print(cell.getStringCellValue() + "");
                        break;
                }
            }
            System.out.println("");
        }

        for(Row r:sheet)
        {
            short minColIx=r.getFirstCellNum();
            short maxColIx=r.getLastCellNum();
            for(short colIx=minColIx;colIx<maxColIx;colIx++) {
                Cell c= r.getCell(colIx);
                if(c!=null) {
                    if(c.getCellType()== Cell.CELL_TYPE_STRING||c.getCellType() == Cell.CELL_TYPE_NUMERIC||c.getCellType() == Cell.CELL_TYPE_BOOLEAN) {
                        count++; ---// can i use hashcode in here to get the key and value pair? key=column index value=total number of rows in that column
                            } 
                    }
                    else break;
                }
            }

        System.out.println("
Total Number of columns are:"+count);
        System.out.println(hm);
        file.close();    
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException ae) {
        ae.printStackTrace();
    }
}
}

Answer 1

Try this:

private void excelReader() {
    String data;
    try {
        InputStream is = new FileInputStream("Read.xlsx");
        Workbook wb = WorkbookFactory.create(is);
        Sheet sheet = wb.getSheetAt(0);
        Iterator rowIter = sheet.rowIterator();
        Row r = (Row)rowIter.next();
        short lastCellNum = r.getLastCellNum();
        int[] dataCount = new int[lastCellNum];
        int col = 0;
        rowIter = sheet.rowIterator();
        while(rowIter.hasNext()) {
            Iterator cellIter = ((Row)rowIter.next()).cellIterator();
            while(cellIter.hasNext()) {
                Cell cell = (Cell)cellIter.next();
                col = cell.getColumnIndex();
                dataCount[col] += 1;
                DataFormatter df = new DataFormatter();
                data = df.formatCellValue(cell);
                System.out.println("Data: " + data);
            }
        }
        is.close();
        for(int x = 0; x < dataCount.length; x++) {
            System.out.println("col " + x + ": " + dataCount[x]);
        }
    }
    catch(Exception e) {
        e.printStackTrace();
        return;
    }
}

Tested code

I created an xlsx file with the following cell data:

Col0    Col1    Col2    Col3    Col4
1       a       x       a       q
2       b       y       s       w
3       c       z       d       e
4       d               f       r
5       e                       t
                                y

The contents of dataCount array is this:

col 0: 6

col 1: 6

col 2: 4

col 3: 5

col 4: 7

The numbers on the right count the number of cells with data for each column, including the header row.

If you want to exclude the header row, just remove the line:

rowIter = sheet.rowIterator();

just before the while loop.

Is this what you are looking for?