private void okActionPerformed(
      java.awt.event.ActionEvent evt) { // GEN-FIRST:event_okActionPerformed

    try {

      if (txtuser.getText().equals("") || txtpassword.getText().equals("")) {

        JOptionPane.showMessageDialog(this, "Please Enter Username & Password", "Message", WIDTH);
      } else { // connect
        Class.forName("com.mysql.jdbc.Driver");
        Connection conn =
            DriverManager.getConnection(
                "jdbc:mysql://localhost:3306/student_information", "root", "123");
        Statement stm = conn.createStatement();
        String qry = "select password from login where username = '******' ;";
        ResultSet rst = stm.executeQuery(qry);

        Statement stm2 = conn.createStatement();
        String qry2 = "select state from login where username = '******'; ";
        ResultSet rst2 = stm2.executeQuery(qry2);

        if (!rst.next()) { // validate username

          JOptionPane.showMessageDialog(this, "Invalid Username", "Error", WIDTH);
        } else if (rst.getString("password").equals(txtpassword.getText())) { // check password

          MainWindow m = new MainWindow(); // open main
          m.setVisible(true);

          m.lbluser.setText(txtuser.getText());

          if (rst2.next() && rst2.getInt("State") == 1) { // block lecturer

            m.lblState.setText("Admin");
          } else {

            m.lblState.setText("Lecturer");
            /* MainWindow mw1 = new MainWindow();
            mw1.btnStudentm.setVisible(false);
            mw1.btnCoursem.setVisible(false);
            mw1.btnLecturerm.setVisible(false);
            mw1.btnAdmin.setVisible(false);
            mw1.lbllec.setVisible(false);*/
          }

          this.setVisible(false);
          txtuser.setText("");
          txtpassword.setText("");

        } else {

          JOptionPane.showMessageDialog(this, "Invalid Password", "Error", WIDTH);
        }
      }

    } catch (Exception e) {

      JOptionPane.showMessageDialog(this, "Error in Excecution " + e, "Error", WIDTH);
    }
  } // GEN-LAST:event_okActionPerformed
示例#2
0
 /**
  * updates the status bar at the bottom of the main window. Just a helper method for this class
  * Was thinking of displaying the last complete transaction, for troubleshooting/demo purposes.
  *
  * @param message - the message to be displayed on the status bar
  */
 private void updateStatusBar(String message) {
   mainWindow.getMyContentPane().setStatusLbl(message);
 }