public static Connection getConnection() throws ClassNotFoundException {
        Connection conn=null;
        try {
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
            String url="";//这里怎么写啊
            conn = DriverManager.getConnection(url , "admin" , "cmsyu");
        }catch (ClassNotFoundException e) {
            e.printStackTrace();
            logger.log(Level.INFO, "----找不到数据库驱动.../n" + e.getMessage());
        } catch (SQLException e) {
            e.printStackTrace();
            logger.log(Level.INFO, "----连接Access数据库错误.../n" + e.getMessage());
        }
        return conn;
    }