Programa En Java

package compilador;
import java.io.*;
public class Chooser extends javax.swing.JFrame {
String k;

public Chooser() {
k="";
initComponents();
}@SuppressWarnings("unchecked")

/////////////////////////////////////////////////////////

private String LeerArchivo(File f){
StringBuffer texto=new StringBuffer();
try {int c;
FileReader entrada=new FileReader(f);
while((c=entrada.read())!=-1){
texto.append((char)c);
}
}catch (IOException ex) {}
returntexto.toString();
}



////////////////////////////////////////////////////////




// <editor-fold defaultstate="collapsed" desc="GeneratedCode">//GEN-BEGIN:initComponents
private void initComponents() {

jFileChooser1 = new javax.swing.JFileChooser();

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);jFileChooser1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {jFileChooser1ActionPerformed(evt);
}
});

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jFileChooser1,javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 0, Short.MAX_VALUE))
);layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()...