为何PreparedStatement.isClosed报错?
这是我的源码:
public void close(){ try{ if(pstm != null && !pstm.isClosed()){ pstm.close(); } if(conn != null && !conn.isClosed()){ conn.close(); } }catch(SQLException sqle){ System.out.println("DBHelper.close:关闭资源出错。"); sqle.printStackTrace(); }}