JDBC-ODBC Bridge, Swing Components

Question

This program displays information from the Access database Autos.mdb.
Uses the JDBC-ODBC Bridge.
Requires a DSN called Autos pointing to Auto.mdb
I am using the swing components and can't seem to set up my combobox to pull the right data which doesn't display any of the data from the database. I am able to do it using AWT but would like a sleeker look so I am trying to convert. I have made the text bold where I am having the problem. Any insight would be greatful! I am very new to JDBC-ODBC so please go easy on me...
import java.sql.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class JDBCApp extends Frame implements ItemListener
     //Declare database variables
     Connection conVehicle;
     Statement cmdVehicle;
     ResultSet rsVehicle;
     boolean blnSuccessfulOpen = false;
     //Declare components
     JComboBox lstManuf   = new JComboBox();
     JLabel lblModel  = new JLabel("                          ");
     JLabel lblYear        = new JLabel("                          ");
     JLabel lblCost      = new JLabel("                          ");
     JLabel lblID      = new JLabel("                              ");
     JLabel lblInstructions = new JLabel("Select Manufacturer to Display Record");
     public static void main(String args[])
          //Declare an instance of this application
          JDBCApp thisApp = new JDBCApp();
          thisApp.createInterface();
     public void createInterface()
          //Load the database and set up the frame
          loadDatabase();
          if (blnSuccessfulOpen)
               setTitle("Display Auto's Database");
               addWindowListener(new WindowAdapter()
                         public void windowClosing(WindowEvent event)
                              stop();
                              System.exit(0);
               setLayout(new FlowLayout());
               add(new JLabel("Manufacturer"));
               add(lstManuf);
               lstManuf.addItemListener(this);
               add(lblInstructions);
               add(new JLabel("Model"));
               add(lblModel);
               add(new JLabel("Year"));
               add(lblYear);
               add(new JLabel("Cost"));
               add(lblCost);
               add(new JLabel("Vehicle Identification"));
               add(lblID);
               setSize(300,300);
               setVisible(true);
          else
               stop();             //Close any open connection
               System.exit(-1);    //Exit with error status
          public void loadDatabase()
               try
                    //Load the MicroSoft drivers
                    Class.forName ("sun.jdbc.odbc.JdbcOdbcDriver");
               catch (ClassNotFoundException err)
                         //No drivers found
                         System.err.println("Driver did not load properly");
               try
                    //Connect to the database
                    conVehicle = DriverManager.getConnection("jdbc:odbc:Auto");
                    //Create a ResultSet
                    cmdVehicle = conVehicle.createStatement();
                    rsVehicle = cmdVehicle.executeQuery(
                                        "Select * from Vehicle;");
                    loadNames(rsVehicle);
                    blnSuccessfulOpen = true;
               catch(SQLException error)
                    System.err.println("Error: " + error.toString());
     public void loadNames(ResultSet rsVehicle)
          try
               //Fill last name list box
               while(rsVehicle.next())
               lstManuf.addItem(rsVehicle.getString("Manufacturer"));
          catch (SQLException error)
               System.err.println("Error in display record");
     public void itemStateChanged(ItemEvent event)
          //Display the selected record
          lblInstructions.setText("");          String strManufName = lstManuf.getText();
          try
               Statement cmdVehicle = conVehicle.createStatement();
               ResultSet rsVehicle = cmdVehicle.executeQuery(
                    "Select * from Vehicle where [Manufacturer] = '" + strManufName + "';");
               DisplayRecord(rsVehicle);
          catch(SQLException error)
               System.err.println("Error in recordset");
      public void DisplayRecord(ResultSet rsVehicle)
           try
               //Display information
               if(rsVehicle.next()) //If more records remain
                    lblModel.setText(rsVehicle.getString("ModelName"));
                    lblYear.setText(rsVehicle.getString("Year"));
                    lblCost.setText(rsVehicle.getString("CostValue"));
                    lblID.setText(rsVehicle.getString("VehicleID"));
               else
                    System.err.println("No more records");
          catch (SQLException error)
               System.err.println("Error in display record");
     public void stop()
          try
               //Terminate the connection
               if (conVehicle != null)
                    conVehicle.close();
          catch(SQLException error)
               System.err.println("Unable to disconnect");
}

Answer 1

I am going to help you out but first I would like to advise you not to do this.
Mixing JDBC and Swing (or any GUI for that matter) like this is not the preferred way to proceed. If you want to learn JDBC then command line/shell is fine. If you want to learn Swing learn Swing. When you want to use the two together learn about MVC first.
I am advising you to do this because nobody writes code like this (mixing GUI and database and business logic all in one class). So if you want real world training MVC should be what you look at next.
See http://en.wikipedia.org/wiki/Model-view-controller for more
As near as I can tell your problem is mostly just because you aren't using the combo box correctly. Try
String strManufName = lstManuf.getSelectedItem().toString();it's a bit of a hack but will work for your purposes. What you need in the eend is to use the methods JComboxBox has like getSelectedItem() or getSelectedIndex().
See http://java.sun.com/docs/books/tutorial/uiswing/components/combobox.html for more.
Some other comments.
1) It's nice to see you aren't just swallowing exceptions but some of them are kind of pointless if you just continue on. Like here
try
  //Load the MicroSoft drivers
  Class.forName ("sun.jdbc.odbc.JdbcOdbcDriver");
catch (ClassNotFoundException err)
  //No drivers found
  System.err.println("Driver did not load properly");
}And then you continue on with the method. What for? There's no point since the driver didn't load.
2) Please look into the use of PreparedStatements. Very good things those. You can use them in place of your Statements. They are safer but for your purposes help you by you not having to worry about the formatting of data you bind to queries. For example what happens if a manufacturer name contains a ' (single quote) ? Trouble that's what. PreparedStatements make that problem go away.
3) Don't use SELECT *. It is always good practice to put the names of the columns you are selecting. This prevents your code from breaking if the order of the columns should change in any way.