Desabilitar o controle Minimizar, ..., Fechar em GWT

import java.awt.Dimension;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JOptionPane;

public class Teste extends JDialog {
	
	public Teste() {
		this.setLocation(300, 200);
		this.setSize(new Dimension(300, 200));
		this.setVisible(true);
		this.setTitle("Teste JDialog");
		this.setResizable(false);
		this.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				JOptionPane.showMessageDialog(null,
					"Essa tela não pode ser fechada", "Aviso",
					JOptionPane.WARNING_MESSAGE);
			}
		});

	}

	public static void main(String[] args) {
		Teste teste = new Teste();
		teste.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
	}
}