Problema com o código da interface, em JFaces

To com problema na parte de variaveis compartilhadas com outras classes

Aqui está meu código da classe mãe:

[code]package code;

import java.util.ArrayList;
import java.util.List;
import javax.swing.JOptionPane;

public class Home {

public List<Double> altura = new ArrayList<Double>();

public void consultar() {
    altura.add(1.56);
    altura.toArray();

    double maior = altura.get(0);
    double menor = altura.get(0);


    for (double valor : altura) {
        if (maior < valor) {
            maior = valor;
        }
        if (menor > valor) {
            menor = valor;
        }
        JOptionPane.showMessageDialog(null, "O Maior é: " + maior );
        JOptionPane.showMessageDialog(null, "O Menor é: " + menor);
    }

}

public void adicionar() {
    double novoValor = Double.parseDouble(JOptionPane.showInputDialog(
            "Informe uma Altura abaixo: "));

    altura.add(novoValor);

}

}[/code]

e aqui a da interface que está vazia!!

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package code;

/**
 *
 * @author bruno
 */
public class Interface extends javax.swing.JFrame {

    /**
     * Creates new form Interface
     */
    public Interface() {
        initComponents();
      
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        addButton = new javax.swing.JButton();
        delButton = new javax.swing.JButton();
        consultarButton = new javax.swing.JButton();
        jScrollPane1 = new javax.swing.JScrollPane();
        saidaArea = new javax.swing.JTextArea();
        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        addButton.setText("Adicionar +");
        addButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                addButtonActionPerformed(evt);
            }
        });

        delButton.setText("Excluir ø");

        consultarButton.setText("&#8592; Consultar &#8594;");

        saidaArea.setColumns(20);
        saidaArea.setRows(5);
        jScrollPane1.setViewportView(saidaArea);

        jLabel1.setText("Men's Size,");

        jLabel2.setText("ßeta 0.01");

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(43, 43, 43)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.CENTER)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(addButton)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(delButton, javax.swing.GroupLayout.PREFERRED_SIZE, 86, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addComponent(consultarButton)
                    .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel1))
                .addGap(57, 57, 57))
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addGap(0, 0, Short.MAX_VALUE)
                .addComponent(jLabel2))
        );

        layout.linkSize(javax.swing.SwingConstants.HORIZONTAL, new java.awt.Component[] {addButton, consultarButton, delButton});

        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jLabel1)
                .addGap(24, 24, 24)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(addButton)
                    .addComponent(delButton))
                .addGap(26, 26, 26)
                .addComponent(consultarButton)
                .addGap(34, 34, 34)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 24, Short.MAX_VALUE)
                .addComponent(jLabel2))
        );

        layout.linkSize(javax.swing.SwingConstants.VERTICAL, new java.awt.Component[] {addButton, consultarButton, delButton});

        pack();
    }// </editor-fold>                        

    private void addButtonActionPerformed(java.awt.event.ActionEvent evt) {                                          
    }                                         

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
       
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /*
         * If Nimbus (introduced in Java SE 6) is not available, stay with the
         * default look and feel. For details see
         * http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(Interface.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Interface.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Interface.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Interface.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /*
         * Create and display the form
         */
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                new Interface().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify                     
    private javax.swing.JButton addButton;
    private javax.swing.JButton consultarButton;
    private javax.swing.JButton delButton;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTextArea saidaArea;
    // End of variables declaration                   
}

Eu sei que existen diversos tutoriais inclusive aqui mas, tentei de tudo (mas resolvi deixar limpa a Classe), e não me acerto com esse List ai,
e se for fazer com array não vai ser do propósito do programa,!

Obrigado!