private String getFormattedNumberString(Cell cell, ConditionalFormattingEvaluator cfEvaluator) {

        Format numberFormat = getFormat(cell, cfEvaluator);
        double d = cell.getNumericCellValue();
        if (numberFormat == null) {
            return String.valueOf(d);
        }
        String formatted = numberFormat.format(new Double(d));
        return formatted.replaceFirst("E(\\d)", "E+$1"); // to match Excel's E-notation
    }
Returns the formatted value of an Excel number as a <tt>String</tt> based on the cell's <code>DataFormat</code>.
Supported formats include currency, percents, decimals, phone number, SSN, etc.: "61.54%", "$100.00", "(800)
555-1234".
<p>
Format comes from either the highest priority conditional format rule with a specified format, or from the cell
style.

@param cell        The cell
@param cfEvaluator if available, or null
@return a formatted number string
fastexcel-test/src/test/java/cn/idev/excel/test/temp/dataformat/DataFormatter1.java