POI-根據Cell獲取對應的String類型值

/**
     * 根據不同情況獲取Java類型值
     * <ul><li>空白類型<ul><li>返回空字符串</li></ul></li></ul><ul><li>布爾類型</li><ul><li>返回Boulean類型值</li></ul></ul><ul><li>錯誤類型</li><ul><li>返回String類型值：Bad value</li></ul></ul><ul><li>數字類型</li><ul><li>日期類型</li><ul><li>返回格式化后的String類型，e.g.2017-03-15 22:22:22</li></ul><li>數字類型</li><ul><li>返回經過處理的java中的數字字符串，e.g.1.23E3==>1230</li></ul></ul> </ul><ul><li>公式類型</li><ul><li>公式正常</li><ul><li>返回計算后的String類型結果</li></ul></ul><ul><li>公式異常</li><ul><li>返回錯誤碼，e.g.#DIV/0!；#NAME?；#VALUE!</li></ul></ul> </ul><ul><li>字符串類型</li><ul><li>返回String類型值</li></ul></ul>
     * 
     * @param cell
     *            XSSFCell類型單元格
     * @return 返回Object類型值
     * @since 2017-03-26 00:05:36{@link #getValueOfNumericCell()}
     */
    public static Object getJavaValue(XSSFCell cell) {
        Object o = null;
        int cellType = cell.getCellType();
        switch (cellType) {
        case XSSFCell.CELL_TYPE_BLANK:
            o = "";
            break;
        case XSSFCell.CELL_TYPE_BOOLEAN:
            o = cell.getBooleanCellValue();
            break;
        case XSSFCell.CELL_TYPE_ERROR:
            o = "Bad value!";
            break;
        case XSSFCell.CELL_TYPE_NUMERIC:
            o = getValueOfNumericCell(cell);
            break;
        case XSSFCell.CELL_TYPE_FORMULA:
            try {
                o = getValueOfNumericCell(cell);
            } catch (IllegalStateException e) {
                try {
                    o = cell.getRichStringCellValue().toString();
                } catch (IllegalStateException e2) {
                    o = cell.getErrorCellString();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            break;
        default:
            o = cell.getRichStringCellValue().getString();
        }
        return o;
    }


    // 獲取數字類型的cell值
    private static Object getValueOfNumericCell(XSSFCell cell) {
        Boolean isDate = DateUtil.isCellDateFormatted(cell);
        Double d = cell.getNumericCellValue();
        Object o = null;
        if (isDate) {
            o = DateFormat.getDateTimeInstance()
                    .format(cell.getDateCellValue());
        } else {
            o = getRealStringValueOfDouble(d);
        }
        return o;
    }

    // 處理科學計數法與普通計數法的字符串顯示，盡最大努力保持精度
    private static String getRealStringValueOfDouble(Double d) {
        String doubleStr = d.toString();
        boolean b = doubleStr.contains("E");
        int indexOfPoint = doubleStr.indexOf('.');
        if (b) {
            int indexOfE = doubleStr.indexOf('E');
            // 小數部分
            BigInteger xs = new BigInteger(doubleStr.substring(indexOfPoint
                    + BigInteger.ONE.intValue(), indexOfE));
            // 指數
            int pow = Integer.valueOf(doubleStr.substring(indexOfE
                    + BigInteger.ONE.intValue()));
            int xsLen = xs.toByteArray().length;
            int scale = xsLen - pow > 0 ? xsLen - pow : 0;
            doubleStr = String.format("%." + scale + "f", d);
        } else {
            java.util.regex.Pattern p = Pattern.compile(".0$");
            java.util.regex.Matcher m = p.matcher(doubleStr);
            if (m.find()) {
                doubleStr = doubleStr.replace(".0", "");
            }
        }
        return doubleStr;
    }