Acionar o botão qnd eu clicar o enter

import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JTextField;


public class Teste extends JFrame {
	private JTextField fldNome;
	private JButton btSair;
	
	public Teste() {
		fldNome= new JTextField();
		btSair= new JButton("Sair");
		Container container = this.getContentPane();
		container.setLayout(new GridLayout(2,2));
		container.add(fldNome);
		container.add(btSair);
		
		fldNome.addActionListener(new ActionListener () {
			@Override
			public void actionPerformed(ActionEvent arg0) {
				btSair.doClick();	//Ativa o botão	
				
			}	
		});
		
		btSair.addActionListener(new ActionListener () {
			@Override
			public void actionPerformed(ActionEvent arg0) {
				JOptionPane.showMessageDialog(null, "Acionei o botão sair.");	
			}	
		});
		
		pack();
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
	
}

public class Principal {
	public static void main(String[] args) {
		Teste t= new Teste();
		t.setVisible(true);
		
	}
	
}