Hello.java

 import javax.swing.*;
 import java.awt.Dimension;

 public class Hola extends JFrame {
     Hola() {
         setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
         setPreferredSize(new Dimension(300, 300));
         add(new JLabel("Hola, mundo en: Java"));
         pack();
     }

     public static void main(String[] args) {
         JTextField titulo = new JTextField("Ejemplo Java.");
         Hola marco = new Hola();
         marco.setTitle(titulo.getText());
         marco.setVisible(true);
     }
 }