java - Java(Netbeans)-如何在if语句中为“访问被拒绝”编码，我尽力了但它没有用..？

需要创建三个用户登录名，一旦登录，每个登录用户都需要具有不同的界面。我的操作按钮脚本如下：

 try {
                Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
                String url="jdbc:sqlserver://localhost:1433;databaseName=77OOP062;user=sa;password=hnd";
                Connection conn= DriverManager.getConnection(url);
                String sql ="Select Type from Users where Username=? and Password=?";
                PreparedStatement pst =conn.prepareStatement(sql);
                pst.setString(1, jTextFieldUserName.getText());
                pst.setString(2, jTextFieldPassword.getText());
                ResultSet rs = pst.executeQuery();
                rs.next();
                String name = rs.getString("Type");





            if (name.equals("admin")) {
            JOptionPane.showMessageDialog(null, "Access Permitted");
        ManageUI ah = new ManageUI();
        ah.setVisible(true);
            }

            if (name.equals("cashier")){
        JOptionPane.showMessageDialog(null, "Access Permitted");
            CashierUI eh = new CashierUI();
            eh.setVisible(true);
    }
            else if (name.equals("stockkeeper")){
            JOptionPane.showMessageDialog(null, "Access Permitted");
        StockKeeperUI aq = new StockKeeperUI();
            aq.setVisible(true);
    }
            conn.close();
        }
       catch (Exception e){
            JOptionPane.showMessageDialog(null, e);
        }


This is my Sql server database: User
-----------------------------------------------
Username | Type         | Password |
-----------------------------------------------
mick     | admin        |   123    |
-----------------------------------------------
nisha    | cashier      |   456    |
-----------------------------------------------
sam      | stockkeeper  |   789    |
-----------------------------------------------

最佳答案

您忘记了以下代码中最后一个没有匹配的内容时的处理方法（如果包含else则在第二个代码中第二个），以完成if else链。

 try {
                Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
                String url="jdbc:sqlserver://localhost:1433;databaseName=77OOP062;user=sa;password=hnd";
                Connection conn= DriverManager.getConnection(url);
                String sql ="Select Type from Users where Username=? and Password=?";
                PreparedStatement pst =conn.prepareStatement(sql);
                pst.setString(1, jTextFieldUserName.getText());
                pst.setString(2, jTextFieldPassword.getText());
                ResultSet rs = pst.executeQuery();
    if(rs.next()){ // Row Exists
                String name = rs.getString("Type");

    if (name.equals("admin")) {
                JOptionPane.showMessageDialog(null, "Access Permitted");
            ManageUI ah = new ManageUI();
            ah.setVisible(true);
                }

                else if (name.equals("cashier")){
            JOptionPane.showMessageDialog(null, "Access Permitted");
                CashierUI eh = new CashierUI();
                eh.setVisible(true);
        }
                else if (name.equals("stockkeeper")){
                JOptionPane.showMessageDialog(null, "Access Permitted");
            StockKeeperUI aq = new StockKeeperUI();
                aq.setVisible(true);
        }else {
                JOptionPane.showMessageDialog(null, "Access Denied");
        }
  } else{
JOptionPane.showMessageDialog(null, "Access Denied"); // Row Doesnot exists
}
    conn.close();
    }
   catch (Exception e){
        JOptionPane.showMessageDialog(null, e);
    }

关于java - Java(Netbeans)-如何在if语句中为“访问被拒绝”编码，我尽力了但它没有用..？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/46334940/