Am I missing a basic point in Swing Gui

Question

Hi,
Why does the text('Hello') not display. ??? The JFrame is empty with no component(JTextField). Here's my code:-
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class DspTxt extends JPanel {
     String txt="Hello" ;
     JTextField jtxt;     
// Constr
     DspTxt(){
     jtxt= new JTextField(txt);
     JPanel panel= new JPanel(new BorderLayout());
     panel.add(jtxt);
     public static void main(String[] args) {
     JFrame mainframe = new JFrame();
          mainframe.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {System.exit(0);}
          DspTxt f= new DspTxt();
          mainframe.getContentPane().add(f);
          mainframe.pack();
          mainframe.setVisible(true);
Thanks in advance
Gurmej

Answer 1

You created a jpanel in your constructor and added the jtextfield to it but you didn't add the jpanel to dsptxt. Dsptxt is a jpanel so you don't need to create a new one.
Run it like this :
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class DspTxt extends JPanel {
     String txt="Hello" ;
     JTextField jtxt;
     // Constr
     DspTxt(){
          jtxt= new JTextField(txt);
          add(jtxt);
     public static void main(String[] args) {
          JFrame mainframe = new JFrame();
          mainframe.addWindowListener(new WindowAdapter() {
               public void windowClosing(WindowEvent e) {System.exit(0);}
          DspTxt f= new DspTxt();
          mainframe.getContentPane().add(f);
          mainframe.pack();
          mainframe.setVisible(true);
}