Using Apache POI how retrieve a numeric cell value as an integer

Question

I have created a program which creates excel sheet, which is having some data column 1 - contains String column 2- contains number (which is basically an integer, but while reading why it is getting converted to Float ?)

    public class ApachePOI8 {

        public static void main(String[] args) {

            String file = "C:\\Eclipse workspace\\PoiExample\\Excel8.xlsx";

            Workbook wb = new XSSFWorkbook();       
            Sheet sheet = wb.createSheet("Sheet1");
            sheet.protectSheet("Pwd1"); //This statements locks the entire sheet with password: Pwd1

            DataFormat fmt = wb.createDataFormat();   //created a textStyle, which prevents Excel to interprate data, in short it means it will be taken as String
            CellStyle textStyle = wb.createCellStyle();
            textStyle.setDataFormat(fmt.getFormat("@"));
            textStyle.setLocked(false);

            CellStyle numerStyle = wb.createCellStyle();
            numerStyle.setDataFormat(fmt.getFormat("0"));
            numerStyle.setLocked(false);


                    Row row0 = CellUtil.getRow(0, sheet);
                    for (int columnIndex = 0; columnIndex<4; columnIndex++){
                        Cell cell = CellUtil.getCell(row0, columnIndex);
                            if(columnIndex == 0) {
                                cell.setCellStyle(textStyle);
                                cell.setCellValue("Product 1");
                            }else if(columnIndex == 1) {                            
                                cell.setCellStyle(numerStyle);
                                cell.setCellValue(1);

                            }
                        }   
                            else{
                                cell.setCellStyle(textStyle);

                            }    
                     } //end of for Loop


            try {
                FileOutputStream outputStream = null;
                outputStream = new FileOutputStream(file);
                wb.write(outputStream);
                outputStream.close();
                System.out.println("Done!");
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }

}

Now to read the excel sheet which got generated

public class ApachePOIExcelRead {

    private static final String FILE_NAME = "C:\\Eclipse workspace\\PoiExample\\Excel8.xlsx";
    public static void main(String[] args) {

        try {
            FileInputStream excelFile = new FileInputStream(new File(FILE_NAME));
            Workbook workbook = new XSSFWorkbook(excelFile);
            Sheet datatypeSheet = workbook.getSheetAt(0);
            Iterator<Row> iterator = datatypeSheet.iterator();

            while (iterator.hasNext()) {

                Row currentRow = iterator.next();
                Iterator<Cell> cellIterator = currentRow.iterator();

                while (cellIterator.hasNext()) {

                    Cell currentCell = cellIterator.next();
                    //getCellTypeEnum shown as deprecated for version 3.15
                    //getCellTypeEnum ill be renamed to getCellType starting from version 4.0
                    if (currentCell.getCellTypeEnum() == CellType.STRING) {
                        System.out.print("String: "+currentCell.getStringCellValue() + "\n");
                    } else if (currentCell.getCellTypeEnum() == CellType.NUMERIC) {
                        System.out.print("NUMERIC "+currentCell.getNumericCellValue() + "\n");
                    }

                }
                System.out.println();

            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

But I am getting the output as String: Product 1 NUMERIC 1.0 String: 12-12-12

Why is it so that the number which is entered i.e 1 is coming in float NUMERIC 1.0?

Kindly suggest.

Answer 1

Answering my own question, as I have got the solution and I hope this might be helpful to others :)

DataFormat format = sheet1.getWorkbook().createDataFormat();
            CellStyle costprice = bulkUploadSpreadSheet.getWorkbook().createCellStyle();
            costprice.setDataFormat(format.getFormat("#"));

Now you can apply the costprice cell style to the desired cell. Please do let me know if you any other solution for this. All the best.

Answer 2

getNumericCellValue() returns a double.

As far as POI is concerned all numeric values are floating point. You can just convert the returned double to int or long if you need it to be an integer, truncating in the process.

System.out.print("NUMERIC " + ((int)currentCell.getNumericCellValue()) + "\n");

But be aware that you may occasionally get surprising results for the numeric values of formula cells, whose operands are non-integers, that "should" produce an integer result. The actual result may not be exactly an integer, and you might end up truncating and be off by 1. For all the gory details read What Every Computer Scientist Should Know About Floating-Point Arithmetic