JFrame accessing Data from the database not showing

Question

I have other classes which perform the task of retrieving the data. I want my jframe to show them but there is a big problem somewhere which causes the program to show blank page!! Here is the Code:

package mySystem;

import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JTable;
import javax.swing.JToolBar;
import javax.swing.JLabel;
import javax.swing.GroupLayout;
import javax.swing.GroupLayout.Alignment;
import javax.swing.LayoutStyle.ComponentPlacement;
import javax.swing.JButton;
import java.awt.GridLayout;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Insets;
import java.sql.*;
import java.util.ArrayList;

import com.jgoodies.forms.layout.FormLayout;
import com.jgoodies.forms.layout.ColumnSpec;
import com.jgoodies.forms.factories.FormFactory;
import com.jgoodies.forms.layout.RowSpec;

public class DisplayCustomers extends JFrame {

    private JPanel contentPane;
    private static Connection con;
    private static ArrayList<Customer> customers;
    private ArrayList<JLabel> name;
    private ArrayList<JLabel> sureName;
    private ArrayList<JButton> accept;
    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    con = DriverManager.getConnection(
                            "jdbc:mysql://my_url", 
                            "user", "pass");
                    Item item = new Item(1987,con);
                    customers = LookUp.findCustomers(item.getId(), con);
                    DisplayCustomers frame = new DisplayCustomers(customers,item,con);
                    frame.setVisible(true);

                } catch (SQLException ex){
                    ex.printStackTrace();
                } catch (Exception e) {
                    e.printStackTrace();

                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public DisplayCustomers(ArrayList<Customer> customers,Item item,Connection con) 
            throws SQLException {

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 583, 409);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(new GridLayout(customers.size(), 4, 2, 5));

        name = new ArrayList<JLabel>();
        sureName = new ArrayList<JLabel>();
        accept = new ArrayList<JButton>();
        Customer buff = null;

        for(int i=0;i < customers.size();i++) {
            buff = customers.get(i); // for the sake of readability

            name.add(new JLabel(buff.getName()));
            sureName.add(new JLabel(buff.getSureName()));
            String butMsg = "Accept";
            if(buff.isValid())
                butMsg = "Customer is invlid";
            accept.add(new JButton(butMsg));
            contentPane.add(name.get(i));
            contentPane.add(sureName.get(i));
            contentPane.add(accept.get(i));


        }
        con.close();


    }
    public void displayError(){
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 583, 409);
        contentPane = new JPanel();
        setContentPane(contentPane);
        JLabel error = new JLabel("Exception Thrown");
        contentPane.add(error);
    }
}

I keep running this using windowbuilder but the button says it's not compiling and it's only previewing the window. So I'm not sure how to properly run it! Also when I placed new Connection inside the constructor it kept giving error about driver not found even though it has been added as .jar file to my build path and every other non Jframe class runs fine. This is my first time using Jframe and it's giving me a really hard time. Any help is appreciated.