Class.forName(className);
时间: 2024-06-01 12:12:27 浏览: 18
This method is used in Java to load and initialize a class dynamically during runtime. It takes a string parameter, which is the fully qualified name of the class (including the package name) that needs to be loaded.
The Class.forName() method loads the specified class and returns a Class object that can be used to create instances of the class or to access its static members. If the class is not found, it throws a ClassNotFoundException.
This method is commonly used in database programming to load the JDBC driver, which is a class provided by the database vendor that implements the JDBC API. By using Class.forName() to load the driver class, the application can work with any database that provides a JDBC driver, without having to hard-code the driver class name in the code.
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检查以下语法错误:<body> 返回 主页
编写人姓名: 胡莲 学号:20212310930228
<% request.setCharacterEncoding("UTF-8"); String sxh = request.getParameter("xh").trim(); String sname = request.getParameter("name").trim(); String sclassname = request.getParameter("classname").trim(); int sage = Integer.parseInt(request.getParameter("age")); String saddress = request.getParameter("address").trim(); String sphone = request.getParameter("phone").trim(); String scity = request.getParameter("city").trim(); String snotes = request.getParameter("notes").trim(); String sql = "update student set name='" + sname + "'" + ",classname='" + sclassname + "'" + ",age='" + sage + "'"+ "'" + ",address='" + saddress + "'"+ "'" + ",phone='" + sphone + "'"+ "'" + ",city='" + scity + "'"+ "'" + ",notes='" + snotes + "'"+ "where xh='" + sxh + "'"; try { java.sql.Connection conn = null; Class.forName("com.mysql.jdbc.Driver").newInstance(); //加载驱动程序 conn = java.sql.DriverManager .getConnection( "jdbc:mysql://localhost:3306/studentdb?useUnicode=true&characterEncoding=utf8", "root", "123456"); //URL指向数据库student PreparedStatement pstatement = conn.prepareStatement(sql); //建立SQL语句 pstatement.execute(); //执行SQL语句 out.print("学生(" + sxh + "," + sname + "," + sclassname + "," + sage + ")");//打印sql out.println("信息更新成功!"); pstatement.close(); conn.close(); } catch (SQLException e1) { System.out.print("sql语句失败!"); e1.printStackTrace(); } catch (Exception e2) { System.out.print("sql语句失败!"); e2.printStackTrace(); } %> </body>
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