Where to place Resultset Code

Question

Hi,
I am using MySQL and I've programmed a next and a previous button, but I'm not getting the pointer to move through the rs properly. I believe that this directly attributable to where I have coded the Resultset. At present the Next and Previous buttons both use the same inner class called NextRecord. NextRecord's constructor is where I have coded the resultset but I think this is the problem. When either button (see ButtonPanel class) is activated it starts a new instance of NextRecord (I think). While I appear to be completely inarticulate, I really need some insight to better structure my code. Here is the code:
import java.sql.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import java.util.*;
import java.text.*;
class InputGridTest1 extends JFrame {
    private DataPanel screenvar;
    private JTextArea msgout;
    private Connection dbconn;
    private ButtonPanel control;
    private int testCount;
     InputGridTest1 () {     // 1
        super("Using MySQL");
        setSize(600, 500);  // width, height
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        // Set up GUI environment
        Container mainForm = getContentPane();          
        screenvar = new DataPanel();                    
        msgout = new JTextArea( 8, 40 );               
        mainForm.setLayout( new FlowLayout() );
        mainForm.add( new JScrollPane( screenvar ) );     
        mainForm.add( new JScrollPane( msgout ) );
       // Set up database connection
       try {
          String url = "jdbc:mysql://xx.xxx.xx.xxx/test?  user=abc&password=efg";
          Class.forName("com.mysql.jdbc.Driver").newInstance();
          dbconn = DriverManager.getConnection( url );
       catch ( ClassNotFoundException cnfex ) {
       // process ClassNotFoundExceptions here
       cnfex.printStackTrace();
       msgout.append( "Connection unsuccessful\n" +
       cnfex.toString() );
       catch ( SQLException sqlex ) {
       // process SQLExceptions here
      sqlex.printStackTrace();
      msgout.append( "Connection unsuccessful\n" +
      sqlex.toString() );
      catch ( Exception excp ) {
     // process remaining Exceptions here
    excp.printStackTrace();
    msgout.append( excp.toString() );
     // Add Find, Add, Update, and Clear buttons
     ButtonPanel controls = new ButtonPanel( dbconn, screenvar,   msgout);
     mainForm.add(controls);
     }     // 1
    public static void main(String[] arguments) {
        InputGridTest1 gridTest1 = new InputGridTest1();
        gridTest1.show();
    class NextRecord implements ActionListener {     // 100
       private DataPanel screenvar;
       private JTextArea msgout;
       private Connection dbconn;
       ResultSet rs = null;
       public NextRecord( Connection dbc, DataPanel scv, JTextArea msg ) {
       dbconn = dbc;
       screenvar = scv;
       msgout = msg;
       try {     // 2
          Statement statement =dbconn.createStatement (ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE);
          String query = "SELECT * FROM addresses ";
          msgout.append( "\nSending query: "   +
          dbconn.nativeSQL( query ) + "\n" );
          rs = statement.executeQuery( query );
//NOTE: is this part of the problem?
    //             statement.close();
          } // 2
          catch ( SQLException sqlex ) {     // 3
          msgout.append( sqlex.toString() + sqlex.getMessage() );
          }     // 3
          }     // 200
          public void actionPerformed( ActionEvent e ) {     // 300
               String command = e.getActionCommand();
               if (command.equals("Next")){
                 try {
                    rs.next();
                 catch ( SQLException sqlex ) {
                 msgout.append( "\n*** Next: This does not work!   ***\n" );
                 display(rs);
               if (command.equals("Previous")){
                 try {
                 rs.previous();
                 msgout.append("Ivebeenevaluated!");
                 catch ( SQLException sqlex ) {
                 msgout.append( "\n*** Previous: This does not work!  ***\n" );
                 display(rs);
                }     // 300
            public void display( ResultSet rs ) { // 100
               try {
                   int recordNumber = 1;
                   if ( recordNumber == 1 ) {
                   screenvar.first.setText( rs.getString( 1 ) );
                   screenvar.last.setText( rs.getString( 2 ) );
                   screenvar.address.setText( rs.getString( 3 ) );
                   screenvar.city.setText( rs.getString( 4 ) );
                   screenvar.state.setText( rs.getString( 5 ) );
                   screenvar.zip.setText( rs.getString( 6 ) );
                else
                msgout.append( "\nNo record found\n" );
               catch ( SQLException sqlex ) {
               msgout.append( "\n*** Phone Number Not In Database   ***\n" );
}     // 100
// end of working code
class DataPanel extends JPanel {     // This class needs to be at end
   JTextField id, first, last, address, home, city, state, zip,
      country, email, fax;
   JLabel lfirst, llast, laddress, lhome, lcity, lstate, lzip,
     lcountry, lemail, lfax;
   public DataPanel() {
     // Label panel
      JPanel labelPanel = new JPanel();
      labelPanel.setLayout(new GridLayout( 10, 1 ) );
     lfirst = new JLabel( "First Name:", 0 );
     labelPanel.add( lfirst);
     llast = new JLabel( "Last Name:", 0 );
     labelPanel.add( llast);
     lhome = new JLabel( "Phone:", 0 );
     labelPanel.add( lhome);
     laddress = new JLabel( "Address:", 0 );
     labelPanel.add( laddress);
     lcity = new JLabel( "City:", 0 );
     labelPanel.add( lcity);
     lstate = new JLabel( "State:", 0 );
     labelPanel.add( lstate);
     lzip = new JLabel( "Zip Code:", 0 );
     labelPanel.add( lzip);
     lcountry = new JLabel( "Country:", 0 );
     labelPanel.add( lcountry);
     lemail = new JLabel( "Email:", 0 );
     labelPanel.add( lemail);
     lfax = new JLabel( "Fax Number:", 0 );
     labelPanel.add( lfax);
      // TextField panel
      JPanel screenvarPanel = new JPanel();
      screenvarPanel.setLayout(
         new GridLayout( 10, 1 ) );
      id = new JTextField( 20) ;
       first = new JTextField( 20 );
      screenvarPanel.add( first );
      last = new JTextField( 20 );
      screenvarPanel.add( last );
       home = new JTextField("Enter number-click Find", 20);
       screenvarPanel.add( home );
       address = new JTextField( 20 );
      screenvarPanel.add( address );
      city = new JTextField( 20 );
      screenvarPanel.add( city );
      state = new JTextField( 20 );
      screenvarPanel.add( state  );
      zip = new JTextField( 20 );
      screenvarPanel.add( zip );
      country = new JTextField( 20 );
      screenvarPanel.add( country );
      email = new JTextField( 20 );
      screenvarPanel.add( email );
      fax = new JTextField( 20 );
      screenvarPanel.add( fax );
      setLayout( new GridLayout( 1, 2 ) );
      add( labelPanel );
      add( screenvarPanel );
class ButtonPanel extends JPanel {     // This class needs to be at end
   public ButtonPanel( Connection dbc, DataPanel scv,
      JTextArea msg ) {
      setLayout( new GridLayout( 1, 4 ) );
       JButton nextRec = new JButton( "Next" );
       nextRec.addActionListener( new NextRecord( dbc, scv, msg ) );
       add( nextRec );
       JButton prevRec = new JButton( "Previous" );
       prevRec.addActionListener( new NextRecord( dbc, scv, msg ) );
       add( prevRec );
       JButton exit = new JButton( "Exit" );
          exit.addActionListener(new ActionListener() { // 1
               public void actionPerformed(ActionEvent e) {     // 2
                 msgout.append( "\n*** This is the Exit Button ***\n" );
                 System.exit(0);
               }     // 2
       });     // 1
       add( exit );
}

Answer 1

Thank you for your reply. I am still pretty new to Java and while I understand conceptually what you are saying, I am having a hard time putting it into practice. So I am hoping that you will bear with me and give me the benefit of your experience. I have created a new object called myConnection which will contain the ResultSet and the next and previous methods. I am lost when it comes to the ButtonPanel constructor, where I have to put a reference to the myConnection object, and how to get the actionlisteners to activate. When I implement actionlistener with myConnection I get an error message that refers to the abstract nature of the object becuase there is no actionperformed() there. Do the next() and previous() methods need to be called by the actionperformed()?
Thanks,
Steve (newbies arghhh!!)
//BEGIN connection object
class myConnection {
     private DataPanel screenvar;
     private JTextArea msgout;
     private Connection dbconn;
     ResultSet rs = null;
     public myConnection( Connection dbc, DataPanel scv, JTextArea msg ) { // 200
    dbconn = dbc;
    screenvar = scv;
    msgout = msg;
          try {     // 2
                  Statement statement =dbconn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE);
                String query = "SELECT * FROM addresses ";
               msgout.append( "\nSending query: "   +
                  dbconn.nativeSQL( query ) + "\n" );
               rs = statement.executeQuery( query );
                 rs.last();
                 statement.close();
              } // 2
         catch ( SQLException sqlex ) {     // 3
                     msgout.append( sqlex.toString() + sqlex.getMessage() );
                  }     // 3
     }     // 200
      public void next() {
          rs.next();
          display(rs);
      public void previous() {
          rs.previous();
          display(rs);
      public void display( ResultSet rs ) { // 100
         try {
            int recordNumber = 1;
            if ( recordNumber == 1 ) {
               screenvar.first.setText( rs.getString( 1 ) );
               screenvar.last.setText( rs.getString( 2 ) );
               screenvar.address.setText( rs.getString( 3 ) );
               screenvar.city.setText( rs.getString( 4 ) );
               screenvar.state.setText( rs.getString( 5 ) );
               screenvar.zip.setText( rs.getString( 6 ) );
            else
               msgout.append( "\nNo record found\n" );
       catch ( SQLException sqlex ) {
          msgout.append( "\n*** Phone Number Not In Database ***\n" );
// BEGIN button class
class ButtonPanel extends JPanel {     // This class needs to be at end
   public ButtonPanel( Connection dbc, DataPanel scv,
      JTextArea msg ) {
      setLayout( new GridLayout( 1, 4 ) );
//  this is where I need to refer to the myConnection class
// I'm lost here
       JButton nextRec = new JButton( "Next" );
       nextRec.addActionListener( new myConnection( dbc, scv, msg ) );
       add( nextRec );
       JButton prevRec = new JButton( "Previous" );
       prevRec.addActionListener( new myConnection( dbc, scv, msg ) );
       add( prevRec );