Passing an array into an Event Handler?

Question

An inventory project I am working on is requiring me to create JButtons (First, Last, Next, and Previous) which are supposed to cycle through and display (in JTextFields) the contents of an array of objects. I can make the buttons work if I do this:
numberfield.setText("This works when used in the event handler");
but it does not work when I try to do this:
numberfield.setText(dirtbikes[0].getNumber());
When I try this, I get this error:
InventoryGUITest2:java:124:cannot find symbol
symbol : variable dirtbikes
location : class InventoryGUITest2
numberfield.setText(dirtbikes[0].getNumber());
^
I'm not sure if what I am trying to do is possible, but any guidance would be greatly appreciated. I have included the code for the main class below. Thank you for your time.
import javax.swing.*; // imports all javax.swing classes
import java.awt.event.*; // imports event handling components
import java.awt.*;
public class InventoryGUITest2 extends JFrame implements ActionListener // class tests an instance of class Inventory using a GUI to display data
     JTextArea textArea;
     JLabel numberlabel, namelabel, speedlabel, pricelabel, stocklabel, restocklabel, valuelabel, totalvaluelabel; // creates JLabels
     JTextField numberfield, namefield, speedfield, pricefield, stockfield, restockfield, valuefield, totalvaluefield; // creates JTextFields
     JButton firstbutton, lastbutton, previousbutton, nextbutton; // creates JButtons for navigation
     public static void main( String args[] ) // begins Java execution
          Dirtbikes dirtbikes[]; // declares array variable
        dirtbikes = new Dirtbikes[4]; //declares array with length of 4
        // populate array
          dirtbikes[0] = new Dirtbikes( "11", "49cc Dirt Bike", 4, 199.99, "25 mph"  );
          dirtbikes[1] = new Dirtbikes( "12", "90cc MotoX Bike", 7, 1299.99, "45+ mph" );
          dirtbikes[2] = new Dirtbikes( "13", "70cc Pit Bike", 3, 359.99, "35+ mph" );
          dirtbikes[3] = new Dirtbikes( "14", "50cc Street Rocket", 5, 879.99, "55+ mph" );
        // end populate array
        new InventoryGUITest2(dirtbikes); // creates new instance of itself
     } // end main method
    // constructor creates and runs GUI
     public InventoryGUITest2(Dirtbikes[] dirtbikes)
        this.setSize(500,300);
          this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          this.setTitle("Dirt Bike Inventory");
          JPanel panel1 = new JPanel(); // creates panel to imbed buttons into bottom of frame
          firstbutton = new JButton("First");
          firstbutton.addActionListener(this);
          panel1.add(firstbutton);
        lastbutton = new JButton("Last");
        lastbutton.addActionListener(this);
        panel1.add(lastbutton);
        previousbutton = new JButton("Previous");
        previousbutton.addActionListener(this);
        panel1.add(previousbutton);
        nextbutton = new JButton("Next");
        nextbutton.addActionListener(this);
        panel1.add(nextbutton);
        this.add(panel1, BorderLayout.SOUTH);
        JPanel panel2 = new JPanel(); // creates panel to imbed labels and fields into frame
        panel2.setLayout(new FlowLayout(FlowLayout.RIGHT));
        numberlabel = new JLabel("Item Number:                                      ");
        numberfield = new JTextField(25);
        numberfield.setEditable(false);
        panel2.add(numberlabel);
        panel2.add(numberfield);
        namelabel = new JLabel("Item Name:                                          ");
        namefield = new JTextField(25);
        namefield.setEditable(false);
        panel2.add(namelabel);
        panel2.add(namefield);
        speedlabel = new JLabel("Top Speed:                                           ");
        speedfield = new JTextField(25);
        speedfield.setEditable(false);
        panel2.add(speedlabel);
        panel2.add(speedfield);
        pricelabel = new JLabel("Price:                                                     ");
        pricefield = new JTextField(25);
        pricefield.setEditable(false);
        panel2.add(pricelabel);
        panel2.add(pricefield);
        stocklabel = new JLabel("# in Stock:                                            ");
        stockfield = new JTextField(25);
        stockfield.setEditable(false);
        panel2.add(stocklabel);
        panel2.add(stockfield);
        restocklabel = new JLabel("Restock Fee (5%):                              ");
        restockfield = new JTextField(25);
        restockfield.setEditable(false);
        panel2.add(restocklabel);
        panel2.add(restockfield);
        valuelabel = new JLabel("Total Value with fee:                          ");
        valuefield = new JTextField(25);
        valuefield.setEditable(false);
        panel2.add(valuelabel);
        panel2.add(valuefield);
        totalvaluelabel = new JLabel("Total Value with fee (for all items):");
        totalvaluefield = new JTextField(25);
        totalvaluefield.setEditable(false);
        panel2.add(totalvaluelabel);
        panel2.add(totalvaluefield);
        this.add(panel2);
        this.setVisible(true); // makes frame visible
          this.setLocationRelativeTo(null); // centers window on screen
     } // end constructor
               public void actionPerformed(ActionEvent e)
                    if (e.getSource() == firstbutton)
                         numberfield.setText(dirtbikes[0].getNumber());
               }

Answer 1

bwilde wrote:
I appreciate the help as everything I thought I had learned about Java has seemed to fall by the wayside in the shadow of making Swing/AWT work properly.You're not the first person to write this, or code like this in the forum. But realize it isn't true. GUI coding isn't a special case -- it's just another example of object-oriented programming. What's really happening is that the training wheels have come off: Writing a simple Swing example is often the first time one is writing anything that is not trivial.