Why cann't setText to a JTextField??

Question

Need your help!
I produce an array of JTextField and add it to a JPanel.
But I can only set text when initialized.
In other place,even I call setText function, it doesn't work.
Who know the reason??
thanks in advance!!
hgs.

Answer 1

the code is like this:
public class JFrame {
JPanel contentPane;
JPanel panel1 = new JPanel();
JTextField jt = new JTextField(20);
JPanel panel2 = new JPanel();
MyClass class = new MyClass();
public JFrame(){
panel1.add(jt);
panel2.add(class);
contentPane = (JPanel)this.getContentPane();
contentPane.add(panel1);
contentPane.add(panel2);
class MyClass{
public MyClass(){
// here if I call setText,It will work
// jt.setText("test");
public otherFunction(){
// here ,it dosen't work
jt.setText("test"); // it throw no exception when running