poi excel cell 获取单元格的值

	/**
	 * 获取单元格的值, 所见即所得(日期未完善)
	 * @param cell
	 * @return
	 */
	public static String getCellValue(Cell cell) {
		if(cell == null)
			return "";
		DataFormatter dataFormatter = new DataFormatter();

		String res = null;

		if(cell.getCellType() == CellType.FORMULA) {
			FormulaEvaluator evaluator = cell.getSheet().getWorkbook().getCreationHelper().createFormulaEvaluator();
			res = dataFormatter.formatCellValue(cell, evaluator);
		} else {
			res = dataFormatter.formatCellValue(cell);
		}
		String dataFormatString = cell.getCellStyle().getDataFormatString();
		if (!StringUtil.isNull(dataFormatString)) {
			if(dataFormatString.matches("@\".+\"")) {
				Pattern p =  Pattern.compile("@\"(.+)\"");
				Matcher m = p.matcher(dataFormatString);
				m.find();
				res = res + m.group(1);
			}
		}

		return res;
	}