code: public static String long2String(long x)
      {
          char[] cArray = long2char(x);
          StringBuilder sbResult = new StringBuilder(cArray.length);
          for (char c : cArray)
          {
              sbResult.append(c);
          }
          return sbResult.toString();
      }
docs: 转换long类型为string
  
  @param x
  @return