public static double getValueAsDouble(Cell cell) {
    if (cell instanceof ByteBufferExtendedCell) {
      return ByteBufferUtils.toDouble(((ByteBufferExtendedCell) cell).getValueByteBuffer(),
        ((ByteBufferExtendedCell) cell).getValuePosition());
    }
    return Bytes.toDouble(cell.getValueArray(), cell.getValueOffset());
  }
Converts the value bytes of the given cell into a double value
@return value as double
hbase-common/src/main/java/org/apache/hadoop/hbase/PrivateCellUtil.java