Number and cell Formatting in apache poi

Question

I am creating excel sheet using apache poi. I have numbers like - 337499.939437217, which I want to show as it is in excel without rounding off. Also the cell format should be n

Answer 1

At first you need to know how to use DataFormats. Then you need to know the guidelines for customizing a number format.

For your number -337499.939437217 which will be displayed rounded with general number format, you could use format #.###############. The # means a digit which will be displayed only if needed (is not leading zero and/or is not zero as last decimal digit) - see guidelines. So the whole format means show up to 15 decimal digits if needed but only as much as needed.

For currency you should really using a built in number format for currency. So the currency symbol depends on the locale settings of Excel. The following BuiltinFormats are usable with apache poi. Using a built in number format you need only the hexadecimal format numbers.

Example:

import java.io.*;

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class CreateNumberFormats {

 public static void main(String[] args) throws Exception {
  Workbook wb = new XSSFWorkbook();

  Sheet sheet = wb.createSheet("format sheet");
  CellStyle style;
  DataFormat format = wb.createDataFormat();
  Row row;
  Cell cell;
  short rowNum = 0;
  short colNum = 0;

  row = sheet.createRow(rowNum++);
  cell = row.createCell(colNum);
  cell.setCellValue(-337499.939437217); // general format

  style = wb.createCellStyle();
  style.setDataFormat(format.getFormat("#.###############")); // custom number format
  row = sheet.createRow(rowNum++);
  cell = row.createCell(colNum);
  cell.setCellValue(-337499.939437217);
  cell.setCellStyle(style);
  row = sheet.createRow(rowNum++);
  cell = row.createCell(colNum);
  cell.setCellValue(123.456789012345);
  cell.setCellStyle(style);
  row = sheet.createRow(rowNum++);
  cell = row.createCell(colNum);
  cell.setCellValue(123456789.012345);
  cell.setCellStyle(style);

  style = wb.createCellStyle();
  style.setDataFormat((short)0x7); // builtin currency format
  row = sheet.createRow(rowNum++);
  cell = row.createCell(colNum);
  cell.setCellValue(-1234.5678);
  cell.setCellStyle(style);

  sheet.autoSizeColumn(0);

  FileOutputStream fileOut = new FileOutputStream("CreateNumberFormats.xlsx");
  wb.write(fileOut);
  fileOut.close();
  wb.close();
 }
}