
String url = "jdbc:mysql:///xuexi";
String user = "root";
String passwd = "123321";
Connection connection = DriverManager.getConnection(url, user, passwd);
Statement statement = connection.createStatement();
Scanner sc = new Scanner(System.in);
String s = sc.next();
sc.nextLine(); //吸收一个空格
String s2 = sc.nextLine();
String sql = "SELECT * FROM userdim WHERE user = ? and passwd = ?";
PreparedStatement preparedStatement = connection.prepareStatement(sql);
preparedStatement.setString(1,s); //将第一个?的值切换成s的值
preparedStatement.setString(2,s2); //将第二个?的值切换成s2的值
ResultSet resultSet = preparedStatement.executeQuery(); //返回查询结果
if(resultSet.next()){
System.out.println("登录成功");
}else {
System.out.println("登录失败");
}