Question

我正在尝试设置一个登录系统，当用户输入用户名和密码并按下登录按钮时，他的用户名和密码将在SQL语句中发送，以便与数据库中的用户匹配。如果用户名和密码正确（如果它们在数据库中匹配），则会创建一个User对象，其中包含来自数据库的所有用户数据，并且用户将被带到Admin Dashboard

在对结果集等进行了大量研究并经历了大量代码之后，我仍然无法使其在我的系统中运行。谁能告诉我一个很好的方法呢？或者告诉我这段代码是否有明显的错误？

当我输入用户名和密码并按登录时，我在控制台中收到错误：

java.sql.SQLException: Invalid column index
    at oracle.jdbc.driver.OraclePreparedStatement.setStringInternal(OraclePreparedStatement.java:5321)
    at oracle.jdbc.driver.OraclePreparedStatement.setString(OraclePreparedStatement.java:5309)
    at oracle.jdbc.driver.OraclePreparedStatementWrapper.setString(OraclePreparedStatementWrapper.java:280)
    at database.UserOperations.validateLog(UserOperations.java:45)
    at gui.Login$2.mouseClicked(Login.java:77)

一些gui代码

    JButton btnLogin = new JButton("Login");
    btnLogin.addMouseListener(new MouseAdapter() {
        public void mouseClicked(MouseEvent e) {

            UserOperations userOperations = new UserOperations();

            ResultSet rset = userOperations.validateLog(textFieldUsername.getText(), textFieldPassword.getText());
            User user = null;
            try {
                if (rset.next()) {
                    user = new User(rset.getInt("userID"), rset.getString("userName"), rset.getString("userPassword"), rset.getString("securityQuestion"), rset.getString("securityAnswer"),
                        rset.getInt("adminRights"), rset.getString("email"), rset.getString("fName"), rset.getString("phoneNumber"), rset.getString("department"));

                    dispose();
                    AdminDashboard admin = new AdminDashboard();
                    admin.setVisible(true);

                }
                else{

                    JOptionPane.showMessageDialog(null, "Login fail!", "Error", JOptionPane.WARNING_MESSAGE);
                }
            } catch (SQLException e2) {
                e2.printStackTrace();
            }

        }
    });

validateLogin（）方法

   public ResultSet validateLog(String username, String userpassword)
{
    try {
        String sql = "SELECT userid, username, userpassword, securityquestion, securityanswer, adminrights, email, fname, phonenumber, department FROM systeuser WHERE username = ? AND userpassword = ?";

        stmt = conn.prepareStatement(sql);
        stmt.setString (2, username);
        stmt.setString (3, userpassword);
        rset = stmt.executeQuery ( );

    }
    catch(Exception e){
        e.printStackTrace ( );
        JOptionPane.showMessageDialog (null, "Login Failed", null, JOptionPane.WARNING_MESSAGE);
    }
    return rset;

}

Answer 1

尝试小写：

user = new User(rset.getInt("userid"), rset.getString("username"), 
    rset.getString("userpassword"), rset.getString("securityquestion"), 
    rset.getString("securityanswer"), rset.getInt("adminrights"), 
    rset.getString("email"), rset.getString("fname"),
    rset.getString("phonenumber"), rset.getString("department"));

而不是混合案例：

user = new User(rset.getInt("userID"), rset.getString("userName"), 
    rset.getString("userPassword"), rset.getString("securityQuestion"), 
    rset.getString("securityAnswer"), rset.getInt("adminRights"), 
    rset.getString("email"), rset.getString("fName"),
    rset.getString("phoneNumber"), rset.getString("department"));

另外，改变这个：

stmt = conn.prepareStatement(sql);
stmt.setString (2, username);
stmt.setString (3, userpassword);

对此：

stmt = conn.prepareStatement(sql);
stmt.setString (1, username);
stmt.setString (2, userpassword);

Answer 2

systeuser

这是你桌子的正确名称吗？

验证结果集中的JTextField数据

2 个答案: