Applet Login via database

[Aqualyn Thomas]

i have created a login applet and i try to connect to my database using JDBC-ODBC...
however i couldn't connect to the database

my codes.....can anyone give me the solution pls

// Java core packages
import java.sql.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.JApplet;
// Java extension packages
import javax.swing.*;
public class TestingLogin extends JApplet
{
private JTextField nameField;
private JPasswordField passwordField;
private JButton loginButton, exitButton;
private JLabel label, label2;
MyJPanel panel = new MyJPanel();

public TestingLogin()
{
//super( "TestingLoginPage" );
Container container = getContentPane();
container.setLayout( new FlowLayout() );

// construct textfield with default sizing
label = new JLabel("Name");
container.add(label);
nameField = new JTextField( 10 );
container.add( nameField );

// construct textfield with default text
label2 = new JLabel("Password");
container.add(label2);
passwordField = new JPasswordField( 10 );
container.add( passwordField );
// register event handlers
TextFieldHandler handler = new TextFieldHandler();
nameField.addActionListener( handler );
passwordField.addActionListener( handler );
// create login button
loginButton = new JButton( "Login" );
container.add( loginButton );
// create exit button
exitButton = new JButton( "Exit" );
container.add( exitButton );

// create an instance of inner class ButtonHandler
loginButton.addActionListener( handler );
exitButton.addActionListener( handler );

setSize( 350, 100 );
setVisible( true );
}
// execute application
public static void main( String args[] )
{
TestingLogin application = new TestingLogin();
// application.setDefaultCloseOperation( JApplet.EXIT_ON_CLOSE );
}
//class to display an ImageIcon on a panel
class MyJPanel extends JPanel
{
private ImageIcon imageIcon;
public MyJPanel()
{
imageIcon = new ImageIcon( "nyp.gif" );
}
}
// private inner class for event handling
private class TextFieldHandler implements ActionListener
{
// process text field events
public void actionPerformed( ActionEvent event )
{
//**************************************************************************************
if (event.getSource()==login)
{
String url = "jdbc dbc:Staffs";
String nameField = "STAFFID";
String passwordField = "PASSWORD";
name=username.getText();
pass=password.getText();
if ( user.length()==0 || pass.length()==0 )
{
JOptionPane.showMessageDialog( null, "Please fill in all values", "Login Error", JOptionPane.ERROR_MESSAGE);
}
else
{
String sql="SELECT Count(*) AS RStotal FROM STAFF WHERE Username='" + user + "' AND Password='" + pass + "'";
String url="jdbc dbc:echo";
try
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection conn = DriverManager.getConnection(url);
Statement login = conn.createStatement();
ResultSet rs = login.executeQuery(sql);
while (rs.next())
{
count = rs.getInt("RStotal");
if(count!=0)
{
setVisible(false);
parent.setVisible(true);
}
else
{
JOptionPane.showMessageDialog( null, "Invalid Username or Password", "Login Error", JOptionPane.ERROR_MESSAGE);
}
}
rs.close();
login.close();
conn.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
//************************************************************************************************
String string = "";
// user pressed Enter in JTextField nameField
if ( event.getSource() == nameField )
string = "nameField: " + event.getActionCommand();

// user pressed Enter in JTextField passwordField
else if ( event.getSource() == passwordField )
{
JPasswordField pwd =
( JPasswordField ) event.getSource();
string = "passwordField: " + new String( passwordField.getPassword() );
}
JOptionPane.showMessageDialog( null,"You pressed: " + event.getActionCommand() );
}
}
}
Thanks in advance

[Maulin Vasavada]

hi,
what exactly u mean when u say "it doesn't work"?
what error u get?
regards
maulin

[Torsten Schippel]

Hi Aqualyn,
here it is:

import java.sql.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.JApplet;
// Java extension packages
import javax.swing.*;
public class TestingLogin
    extends JApplet
    implements ActionListener {
  private JTextField nameField;
  private JPasswordField passwordField;
  private JButton loginButton, exitButton;
  private JLabel label, label2;
  MyJPanel panel = new MyJPanel();
  public TestingLogin() {
//super( "TestingLoginPage" );
    Container container = getContentPane();
    container.setLayout(new FlowLayout());
// construct textfield with default sizing
    label = new JLabel("Name");
    container.add(label);
    nameField = new JTextField(10);
    container.add(nameField);
// construct textfield with default text
    label2 = new JLabel("Password");
    container.add(label2);
    passwordField = new JPasswordField(10);
    container.add(passwordField);
// register event handlers
    nameField.addActionListener(this);
    passwordField.addActionListener(this);
// create login button
    loginButton = new JButton("Login");
    container.add(loginButton);
// create exit button
    exitButton = new JButton("Exit");
    container.add(exitButton);
// create an instance of inner class ButtonHandler
    loginButton.addActionListener(this);
    exitButton.addActionListener(this);
    setSize(350, 100);
    setVisible(true);
  }
// execute application
  public static void main(String args[]) {
    TestingLogin application = new TestingLogin();
// application.setDefaultCloseOperation( JApplet.EXIT_ON_CLOSE );
  }
//class to display an ImageIcon on a panel
  class MyJPanel
      extends JPanel {
    private ImageIcon imageIcon;
    public MyJPanel() {
      imageIcon = new ImageIcon("nyp.gif");
    }
  }
// process text field events
  public void actionPerformed(ActionEvent event) {
//**************************************************************************************
     if (event.getSource() == loginButton) { //login ->loginButton
       String url = "jdbc :-o	 dbc:Staffs";
       //String nameField = "STAFFID";
       //String passwordField = "PASSWORD";
       String name = nameField.getText();
       String pass = passwordField.getText();
       if (name.length() == 0 || pass.length() == 0) {
         JOptionPane.showMessageDialog(null, "Please fill in all values",
                                       "Login Error",
                                       JOptionPane.ERROR_MESSAGE);
       }
       else {
         String sql =
             "SELECT Count(*) AS RStotal FROM STAFF WHERE Username='" + name +
             "' AND Password='" + pass + "'";
         try {
           Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
           Connection conn = DriverManager.getConnection(url);
           Statement login = conn.createStatement();
           ResultSet rs = login.executeQuery(sql);
           while (rs.next()) {
             int count = rs.getInt("RStotal");
             if (count != 0) {
               setVisible(false);
               //parent.setVisible(true); //what ever should happen here
             }
             else {
               JOptionPane.showMessageDialog(null,
                                             "Invalid Username or Password",
                                             "Login Error",
                                             JOptionPane.ERROR_MESSAGE);
             }
           }
           rs.close();
           login.close();
           conn.close();
         }
         catch (Exception e) {
           e.printStackTrace();
         }
       }
     }
//************************************************************************************************
     String string = "";
// user pressed Enter in JTextField nameField
    if (event.getSource() == nameField) {
      string = "nameField: " + event.getActionCommand();
// user pressed Enter in JTextField passwordField
    }
    else if (event.getSource() == passwordField) {
      JPasswordField pwd =
          (JPasswordField) event.getSource();
      string = "passwordField: " + new String(passwordField.getPassword());
    }
    JOptionPane.showMessageDialog(null,
                                  "You pressed: " + event.getActionCommand());
  }
}  

I've made some changes, first I removed the TextFieldHandler and set the applet as handler. It's just easier access to the applet components.
Next "cannot resolve symbol" means the system doesn't know the type or it can't use it. So you need to declare name and pass as String like sql (former posting). Additional I made some ohter small changes. Try to understand it
BTW, MyJPanel is never used.
It's now working with ODBC source Staffs and table named STAFF.
Regards
Torsten