Dúvidas com redimensionar componentes JavaFX

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SpringLayout;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.Dimension;
import java.awt.event.ActionEvent;

public class FormSpringLayout extends JFrame implements ActionListener {

	private SpringLayout s = new SpringLayout();
	private JLabel lblNome = new JLabel("Nome");
	private JTextField txtNome = new JTextField();
	private JButton btnFechar = new JButton("Fechar");
	
	public FormSpringLayout() {
				
		this.setLayout(s);
		this.add(lblNome);
		this.add(txtNome);
		this.add(btnFechar);
		
		txtNome.setPreferredSize(new Dimension(200, 25));

		s.putConstraint(SpringLayout.NORTH,  txtNome, 20, SpringLayout.NORTH, getContentPane());
		s.putConstraint(SpringLayout.WEST,  txtNome, 80, SpringLayout.WEST, getContentPane());
			
		s.putConstraint(SpringLayout.EAST, lblNome, -5, SpringLayout.WEST, txtNome);
		s.putConstraint(SpringLayout.BASELINE, lblNome, 0, SpringLayout.BASELINE, txtNome);

		s.putConstraint(SpringLayout.EAST, btnFechar, 0, SpringLayout.EAST, txtNome);
		s.putConstraint(SpringLayout.NORTH, btnFechar, 20, SpringLayout.SOUTH, txtNome);
		
		s.putConstraint (SpringLayout.EAST, getContentPane(), 20, SpringLayout.EAST, txtNome);
		s.putConstraint (SpringLayout.SOUTH, getContentPane(), 20, SpringLayout.SOUTH, btnFechar);
		
		pack();
		setLocationRelativeTo(null);
		btnFechar.addActionListener(this);
	}
	
	@Override
	public void actionPerformed(ActionEvent evento) {
		if (evento.getSource() == btnFechar)
			dispose();
	}	
	
	public static void main(String[] args) {
		(new FormSpringLayout()).setVisible(true);
	}	
}