this method is meant as an aid to help convert complex html tables to POI (Excel). it accepts the current sheet and row, but keeps count of where your next column will be, colspans and rowspans are included, this method takes advantage of addMergedRegion(...)

HTML to POI Method

/**
 * adds a new cell to the current excel sheet with the HTML translated col- and row spans.
 * @param sheet the current HSSFSheet
 * @param row the current HSSFRow.
 * @param style the style for this cell
 * @param value the cell value.
 * @param rowNum the current row number.
 * @param colNum the current column number.
 * @param rowSpan should there be a row-span here.
 * @param colSpan should there be a col-span here.
 * @return the next column index.
 */
private static int addCell(HSSFSheet sheet, HSSFRow row, HSSFCellStyle style, String value,
        int rowNum, int colNum, int rowSpan, int colSpan) {
    if (row == null) {
        return -1;
    }

    final boolean shouldRowSpan = rowSpan > 1;
    final boolean shouldColSpan = colSpan > 1;

    // new column number
    int updatedColumn = colNum;

    HSSFCell cell = row.createCell(updatedColumn++);
    if (style != null) {
        // set the cell style
        cell.setCellStyle(style);
    }

    // set the value to show
    cell.setCellValue(value);

    // calculate the spans
    if (shouldRowSpan || shouldColSpan) {
        // add the row- and colspans
        sheet.addMergedRegion(new CellRangeAddress(
                (rowNum - 1), (rowNum - 1) + (shouldRowSpan ? rowSpan - 1 : 0),
                (updatedColumn - 1), (updatedColumn - 1) + (shouldColSpan ? colSpan - 1 : 0)
        ));

        if (shouldColSpan) {
            // increment updated column according to colspan
            updatedColumn += (colSpan - 1);
        }
    }

    return updatedColumn;
}