import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.border.BevelBorder;

public class FrmPrincipal extends JFrame {

private static final long serialVersionUID = 1L;
private JButton jButton = new JButton("presioname");
private JTextField jLabel = new JTextField("respuesat");

public FrmPrincipal() {
intialise();
}

public void intialise() {
jLabel.setBorder(new BevelBorder(BevelBorder.RAISED));
jButton.addActionListener(new ActionListener() {

@Override
public void actionPerformed(ActionEvent e) {
jbuton_actionPerformed(e);
}
});
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setLayout(new FlowLayout());
getContentPane().add(jLabel);
getContentPane().add(jButton);

pack();
}

public void jbuton_actionPerformed(ActionEvent e) {
FrmProducto frmData = new FrmProducto(this, true);
frmData.setVisible(true);
String respuesta = frmData.getDato();
jLabel.setText(respuesta);
}

public static void main(String arg[]) {
FrmPrincipal frmPrincipal = new FrmPrincipal();
frmPrincipal.setVisible(true);
}
}

import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JTextField;

public class FrmProducto extends JDialog {

private static final long serialVersionUID = 1L;
private JTextField jTextField = new JTextField("ingrese aqui el dato");

public FrmProducto(JFrame frame, Boolean modal) {
super(frame, modal);
initialise();
}

public void initialise() {
getContentPane().add(jTextField);
pack();
}

public String getDato() {
return jTextField.getText();
}
}