public Object getValueAt(int row, int column) {
    if (row < 0 || row > this.rows.size() ||
      column < 0 || column > this.getColumnCount()) {
      return null;
    }

    Vector r = (Vector) this.rows.elementAt(row);
    Object value = r.elementAt(column);
    if (value instanceof byte[]) {
      byte[] byteValue = (byte[]) value;
      value = "byte[" + byteValue.length + "]";
    }
    return value;
  }