java 转换科学计数法数字

public String getValue(String num) {
  NumberFormat fomatter = new DecimalFormat();
  String[] dataList = fomatter.format(
    Double.parseDouble(String.valueOf(num))).split(",");
  StringBuffer sb = new StringBuffer();
  for (int i = 0; i < dataList.length; i++) {
   sb.append(dataList[i]);
  }
  return sb.toString();
 }