Codigo Formulario En Java

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.ImageIcon;
import javax.swing.JFileChooser;
import javax.swing.JMenuBar;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
importjavax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JButton;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

import javax.swing.JToolBar;


public classEnsamblador extends JFrame {

private JPanel contentPane;

/**
* Launch the application.
*/
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
try {
Ensamblador frame = new Ensamblador();
frame.setVisible(true);
} catch (Exception e)
{
e.printStackTrace();
}
}
});}

/**
* Create the frame.
*/
String StrGuadar = "";
boolean Estado = false;
public Ensamblador()
{

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 596, 523);

JMenuBar menuBar = new JMenuBar();
setJMenuBar(menuBar);

contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));setContentPane(contentPane);
contentPane.setLayout(new BorderLayout(0, 0));

JPanel panel = new JPanel();
contentPane.add(panel, BorderLayout.CENTER);
panel.setLayout(new BorderLayout(0, 0));

JScrollPane scrollPane = new JScrollPane();
panel.add(scrollPane, BorderLayout.CENTER);

final JTextArea textArea = new JTextArea();
scrollPane.setViewportView(textArea);

JToolBartoolBar = new JToolBar();
toolBar.setFloatable(false);
scrollPane.setColumnHeaderView(toolBar);

JButton cmdNuevo = new JButton("");
cmdNuevo.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
String TempText ="";
TempText = textArea.getText();
if (textArea.getText().equals(""))
{
TempText ="";textArea.setText("");
}
else
{
int confirmado = JOptionPane.showConfirmDialog(new JPanel(),"¿Desea guardar los cambios?");

if (JOptionPane.OK_OPTION == confirmado)
{
JFileChooser jF1= new JFileChooser();
String ruta = "";
String Todo = "";
try
{if(jF1.showSaveDialog(null)==JFileChooser.APPROVE_OPTION)
{
ruta = jF1.getSelectedFile().getAbsolutePath();
Todo = textArea.getText();

if (new File(ruta + ".asm").exists())
{

int confirmado2 = JOptionPane.showConfirmDialog(new JPanel(),"¿Ya existe un archivo con ese nombre, desea sobreescribirlo?");

if(JOptionPane.OK_OPTION == confirmado2)
{
FileWriter archi = new FileWriter (ruta + ".asm");
archi.write(Todo);
archi.close();
StrGuadar = ruta;
Estado= true;
}
if (JOptionPane.CANCEL_OPTION == confirmado2)
{
textArea.setText(TempText);
TempText="";
}else
{
textArea.setText("");
TempText="";
StrGuadar = "";
Estado= false;
}


}
else
{
FileWriter archi = new FileWriter (ruta + ".asm");
archi.write(Todo);
archi.close();
}

}...