Hola buenas a todos, El problema es que no consigo que el JTextField muestre por pantalla un simple texto. Se como se utiliza el setText pero no comprendo por que no me funciona en este programa. El apartado grafico lo e generado automaticamente con el asistente(creo que hay puede estar el problema) Le dado mil vueltas y nada. Espero que podais ayudarme. Gracias.

public class MaquinaExpendedora2 extends javax.swing.JFrame {

public MaquinaExpendedora2() {
initComponents();
}

// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {

jPanel1 = new javax.swing.JPanel();
jPanel2 = new javax.swing.JPanel();
jPanel3 = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
jPanel4 = new javax.swing.JPanel();
jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
jButton3 = new javax.swing.JButton();
jButton4 = new javax.swing.JButton();
jButton5 = new javax.swing.JButton();
jButton6 = new javax.swing.JButton();
jButton7 = new javax.swing.JButton();
jButton8 = new javax.swing.JButton();
jButton9 = new javax.swing.JButton();
jButtonC = new javax.swing.JButton();
jButton0 = new javax.swing.JButton();
jButtonAl = new javax.swing.JButton();
pantalla = new javax.swing.JTextField();
jButton10 = new javax.swing.JButton();
jPanel8 = new javax.swing.JPanel();
cincoEuros2 = new javax.swing.JButton();
diezEuros2 = new javax.swing.JButton();
dosCent2 = new javax.swing.JButton();
unCent2 = new javax.swing.JButton();
cincoCent2 = new javax.swing.JButton();
diezCent2 = new javax.swing.JButton();
veinteCent2 = new javax.swing.JButton();
cincuentaCent2 = new javax.swing.JButton();
unEuro2 = new javax.swing.JButton();
dosEuros2 = new javax.swing.JButton();

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

jPanel1.setBackground(new java.awt.Color(0, 0, 0));

jPanel2.setBackground(new java.awt.Color(204, 204, 204));

jLabel1.setIcon(new javax.swing.ImageIcon("C:\\Users\\Usuario\\Desktop\\Productos3.jpg")); // NOI18N

javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3);
jPanel3.setLayout(jPanel3Layout);
jPanel3Layout.setHorizontalGroup(
jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
jPanel3Layout.setVerticalGroup(
jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);

jPanel4.setLayout(new java.awt.GridLayout(4, 3));

jButton1.setText("1");
jPanel4.add(jButton1);

jButton2.setText("2");
jPanel4.add(jButton2);

jButton3.setText("3");
jPanel4.add(jButton3);

jButton4.setText("4");
jPanel4.add(jButton4);

jButton5.setText("5");
jPanel4.add(jButton5);

jButton6.setText("6");
jPanel4.add(jButton6);

jButton7.setText("7");
jPanel4.add(jButton7);

jButton8.setText("8");
jPanel4.add(jButton8);

jButton9.setText("9");
jPanel4.add(jButton9);

jButtonC.setText("C");
jPanel4.add(jButtonC);

jButton0.setText("0");
jPanel4.add(jButton0);

jButtonAl.setFont(new java.awt.Font("Tahoma", 0, 10)); // NOI18N
jButtonAl.setText("#");
jPanel4.add(jButtonAl);

pantalla.setEditable(false);
pantalla.setBackground(new java.awt.Color(51, 255, 0));
pantalla.setHorizontalAlignment(javax.swing.JTextField.RIGHT);

jButton10.setBorder(javax.swing.BorderFactory.createMatteBorder(1, 1, 1, 1, new java.awt.Color(255, 102, 0)));

javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
jPanel2.setLayout(jPanel2Layout);
jPanel2Layout.setHorizontalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(33, 33, 33)
.addComponent(jPanel3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(30, 30, 30)
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jPanel4, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(pantalla))
.addContainerGap(25, Short.MAX_VALUE))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel2Layout.createSequentialGroup()
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jButton10, javax.swing.GroupLayout.PREFERRED_SIZE, 15, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(76, 76, 76))))
);
jPanel2Layout.setVerticalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(32, 32, 32)
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addComponent(pantalla, javax.swing.GroupLayout.PREFERRED_SIZE, 29, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(47, 47, 47)
.addComponent(jPanel4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(jButton10, javax.swing.GroupLayout.PREFERRED_SIZE, 63, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(jPanel3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap(129, Short.MAX_VALUE))
);

jPanel8.setBackground(new java.awt.Color(255, 0, 0));

cincoEuros2.setText("5€");

diezEuros2.setText("10€");

dosCent2.setText("2c");

unCent2.setText("1c");

cincoCent2.setText("5c");

diezCent2.setText("10c");

veinteCent2.setText("20c");

cincuentaCent2.setText("50c");

unEuro2.setText("1€");

dosEuros2.setText("2€");

javax.swing.GroupLayout jPanel8Layout = new javax.swing.GroupLayout(jPanel8);
jPanel8.setLayout(jPanel8Layout);
jPanel8Layout.setHorizontalGroup(
jPanel8Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel8Layout.createSequentialGroup()
.addGap(19, 19, 19)
.addGroup(jPanel8Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel8Layout.createSequentialGroup()
.addComponent(unEuro2, javax.swing.GroupLayout.PREFERRED_SIZE, 51, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(dosEuros2, javax.swing.GroupLayout.PREFERRED_SIZE, 51, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel8Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(diezEuros2, javax.swing.GroupLayout.DEFAULT_SIZE, 123, Short.MAX_VALUE)
.addComponent(cincoEuros2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel8Layout.createSequentialGroup()
.addGroup(jPanel8Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel8Layout.createSequentialGroup()
.addComponent(cincoCent2, javax.swing.GroupLayout.PREFERRED_SIZE, 51, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(diezCent2, javax.swing.GroupLayout.PREFERRED_SIZE, 51, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel8Layout.createSequentialGroup()
.addComponent(unCent2, javax.swing.GroupLayout.PREFERRED_SIZE, 51, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(dosCent2, javax.swing.GroupLayout.PREFERRED_SIZE, 51, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGap(13, 13, 13))
.addGroup(jPanel8Layout.createSequentialGroup()
.addComponent(veinteCent2, javax.swing.GroupLayout.PREFERRED_SIZE, 51, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(cincuentaCent2, javax.swing.GroupLayout.PREFERRED_SIZE, 51, javax.swing.GroupLayout.PREFERRED_SIZE))))
.addContainerGap(21, Short.MAX_VALUE))
);
jPanel8Layout.setVerticalGroup(
jPanel8Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel8Layout.createSequentialGroup()
.addGap(20, 20, 20)
.addComponent(cincoEuros2, javax.swing.GroupLayout.PREFERRED_SIZE, 55, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(diezEuros2, javax.swing.GroupLayout.PREFERRED_SIZE, 58, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addGroup(jPanel8Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(dosCent2, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(unCent2, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel8Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(cincoCent2, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(diezCent2, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel8Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(veinteCent2, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(cincuentaCent2, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel8Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(unEuro2, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(dosEuros2, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap(23, Short.MAX_VALUE))
);

javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(104, 104, 104)
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(jPanel8, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(63, Short.MAX_VALUE))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(45, 45, 45)
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(86, 86, 86)
.addComponent(jPanel8, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(29, Short.MAX_VALUE))
);

getContentPane().add(jPanel1, java.awt.BorderLayout.CENTER);

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

public static void main(String args[]) {

java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new MaquinaExpendedora2().setVisible(true);
}
});

MaquinaExpendedora2 me2 = new MaquinaExpendedora2();

me2.pantalla.setText("Bienvenidos");

}

// Variables declaration - do not modify
private javax.swing.JButton cincoCent;
private javax.swing.JButton cincoCent1;
private javax.swing.JButton cincoCent2;
private javax.swing.JButton cincoEuros;
private javax.swing.JButton cincoEuros1;
private javax.swing.JButton cincoEuros2;
private javax.swing.JButton cincuentaCent;
private javax.swing.JButton cincuentaCent1;
private javax.swing.JButton cincuentaCent2;
private javax.swing.JButton diezCent;
private javax.swing.JButton diezCent1;
private javax.swing.JButton diezCent2;
private javax.swing.JButton diezEuros;
private javax.swing.JButton diezEuros1;
private javax.swing.JButton diezEuros2;
private javax.swing.JButton dosCent;
private javax.swing.JButton dosCent1;
private javax.swing.JButton dosCent2;
private javax.swing.JButton dosEuros;
private javax.swing.JButton dosEuros1;
private javax.swing.JButton dosEuros2;
private javax.swing.JButton jButton0;
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton10;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JButton jButton4;
private javax.swing.JButton jButton5;
private javax.swing.JButton jButton6;
private javax.swing.JButton jButton7;
private javax.swing.JButton jButton8;
private javax.swing.JButton jButton9;
private javax.swing.JButton jButtonAl;
private javax.swing.JButton jButtonC;
private javax.swing.JLabel jLabel1;
private javax.swing.JPanel jPanel1;
private javax.swing.JPanel jPanel2;
private javax.swing.JPanel jPanel3;
private javax.swing.JPanel jPanel4;
private javax.swing.JPanel jPanel6;
private javax.swing.JPanel jPanel7;
private javax.swing.JPanel jPanel8;
private javax.swing.JTextField pantalla;
private javax.swing.JButton unCent;
private javax.swing.JButton unCent1;
private javax.swing.JButton unCent2;
private javax.swing.JButton unEuro;
private javax.swing.JButton unEuro1;
private javax.swing.JButton unEuro2;
private javax.swing.JButton veinteCent;
private javax.swing.JButton veinteCent1;
private javax.swing.JButton veinteCent2;
// End of variables declaration
}

Muchisimas gracias por tu ayuda loderain. Llevo poco programando y ando bastante perdido aun. Gracias a ti puedo seguir avanzando. Y gracias tambien por la explicacion, me a sido de mucha ayuda. Gracias !!Gracias !!