How to insert a row between two rows in an existing excel with HSSF (Apache POI)

Question

Somehow I manage to create new rows between two rows in an existing excel file. The problem is, some of the formatting were not include along the shifting of the rows.

Answer 1

Referencing Qwerty's answer, you can avoid to inflate XL size by re-using cellStyle. And when the type is CELL_TYPE_BLANK, getStringCellValue returns "" instead of null.

private static void copyRow(Sheet worksheet, int sourceRowNum, int destinationRowNum) {
  // Get the source / new row
  Row newRow = worksheet.getRow(destinationRowNum);
  Row sourceRow = worksheet.getRow(sourceRowNum);

  // If the row exist in destination, push down all rows by 1 else create a new row
  if (newRow != null) {
    worksheet.shiftRows(destinationRowNum, worksheet.getLastRowNum(), 1);
  } else {
    newRow = worksheet.createRow(destinationRowNum);
  }

  // Loop through source columns to add to new row
  for (int i = 0; i < sourceRow.getLastCellNum(); i++) {
    // Grab a copy of the old/new cell
    Cell oldCell = sourceRow.getCell(i);
    Cell newCell = newRow.createCell(i);

    // If the old cell is null jump to next cell
    if (oldCell == null) {
      newCell = null;
      continue;
    }

    // Use old cell style
    newCell.setCellStyle(oldCell.getCellStyle());

    // If there is a cell comment, copy
    if (newCell.getCellComment() != null) {
      newCell.setCellComment(oldCell.getCellComment());
    }

    // If there is a cell hyperlink, copy
    if (oldCell.getHyperlink() != null) {
      newCell.setHyperlink(oldCell.getHyperlink());
    }

    // Set the cell data type
    newCell.setCellType(oldCell.getCellType());

    // Set the cell data value
    switch (oldCell.getCellType()) {
    case Cell.CELL_TYPE_BLANK:
      break;
    case Cell.CELL_TYPE_BOOLEAN:
      newCell.setCellValue(oldCell.getBooleanCellValue());
      break;
    case Cell.CELL_TYPE_ERROR:
      newCell.setCellErrorValue(oldCell.getErrorCellValue());
      break;
    case Cell.CELL_TYPE_FORMULA:
      newCell.setCellFormula(oldCell.getCellFormula());
      break;
    case Cell.CELL_TYPE_NUMERIC:
      newCell.setCellValue(oldCell.getNumericCellValue());
      break;
    case Cell.CELL_TYPE_STRING:
      newCell.setCellValue(oldCell.getRichStringCellValue());
      break;
    }
  }
}