Salvar arquivo antes de sair

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

public class FrameLogin extends FrameInicial{

	
	PanelLogin pl;
	
	public FrameLogin(Cofrinho cof, String nomeAr){
		setTitle("Tela de Login");
		this.add(pl = new PanelLogin(this, cof, nomeAr));
		this.pack();
		this.add(pl);
		this.setLocationRelativeTo(null);
		this.setLayout(null);
		this.setContentPane(pl);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setVisible(true);
		this.setResizable(false);
		this.setSize(pl.getSize());
	}
	
	public void fechaJanela(){
		this.setVisible(false);
		this.dispose();
	}
	
	
class PanelLogin extends PanelInicial{
	
	JPasswordField pf;
	JTextField tf;
	JButton ok;
	String nome;
	String senha;
	String s;
	boolean statusNome;
	boolean statusSenha;
	private JFrame frame;
	JLabel tx1;
	JLabel pf1;
	private Cofrinho c;
	int count = 0;
	String nomeArquivo;
	
	public PanelLogin(JFrame f, Cofrinho cof, String nomeAr){
		super(f);
		nomeArquivo = nomeAr;
		c = cof;
		frame = f;
		
		tx1 = new JLabel("Digite o nome");
		tf = new JTextField("************"); 
        tf.addActionListener(this);
		
        pf1 = new JLabel("Digite a senha");
		pf = new JPasswordField("*********");     
        pf.addActionListener(this);
        
        ok = new JButton("Seguir"); 
        ok.addActionListener(this);
        
        JPanel buttonPanel = new JPanel(); //use FlowLayout
        JPanel buttonPanel2 = new JPanel();
        JPanel buttonPanel3 = new JPanel();
        
            buttonPanel.add(tx1);
            buttonPanel.add(tf);
	        buttonPanel2.add(pf1);
	        buttonPanel2.add(pf);
	        buttonPanel3.add(ok);
	        
	        add(buttonPanel, BorderLayout.PAGE_START);
	        add(buttonPanel2, BorderLayout.CENTER);
	        add(buttonPanel3, BorderLayout.PAGE_END);
	}
	
	public boolean validaLogin(String login, String senha){
		
		boolean usuario = false;
		boolean adm = false;
		
		if(c.getNome().equals(login) == true && c.getSenha().equals(senha)){
			usuario = true;
		}
		
			if(login.equals(c.getNomeAdm()) == true && senha.equals(c.getSenhaAdm()) == true){
				adm = true;
			}
				
			if(usuario == true | adm == true)
				return true;
			
			
			else
				return false;
		
	}
	
    private void gravaObjeto (File f, Cofrinho o){
        try	{
            FileOutputStream fos = new FileOutputStream (f);
            ObjectOutputStream os = new ObjectOutputStream (fos);
            os.writeObject (o);
            os.close ();
        }catch (IOException e)  {
                System.out.println ("Erro ao gravar objeto.");
        }
    }

	public void actionPerformed(ActionEvent e) {
		String resp;
		boolean status;
		
		if(c != null)
		if(e.getSource() == ok){
			if(c.getNome() != null && c.getSenha() != null && count < 2){
				resp = new String(pf.getPassword());
				status = this.validaLogin(tf.getText(), resp);
				if(status == true){
				FramePrincipal fp = new FramePrincipal(c);
				this.setVisible(false); // Faz "desaparecer" essa janela
				this.fecha();
				}
				else if(status == false){
					JOptionPane.showMessageDialog(null, "Nome, ou senha Incorretos!", "Failed to Login!", JOptionPane.ERROR_MESSAGE);
					count++;
				}
					
			}
			
			else if(count >= 2){
				JOptionPane.showMessageDialog(null, "O programa vai ser encerrado!", "Failed to Login!", JOptionPane.ERROR_MESSAGE);
				c.setNome(c.getNomeAdm()); // seta os nomes para o de administrador
				c.setSenha(c.getSenhaAdm()); // set's
				File f = new File(nomeArquivo); // cria um file com o nome do arquivo ja carregado
				this.gravaObjeto(f, c); // grava o arquivo
				fecha();
				System.exit(0);
			}
			
			else{
				c = new Cofrinho();
				resp = new String(tf.getText());
				c.setNome(resp);
				resp = new String(pf.getPassword());
				c.setSenha(resp);
				status = this.validaLogin(tf.getText(), resp);
				if(status == true){
				FramePrincipal fp = new FramePrincipal(c);
				this.setVisible(false);
				this.fecha();
				}
			}
				
		}

}
	public void fecha(){
		frame.dispose();
	}
}
}