private static void exportaProductos(ArrayList p){
ObjectOutputStream fichero = null;
try {
fichero = new ObjectOutputStream(new FileOutputStream("productos.mio"));
for(int x = 0; x<p.size(); x++){
fichero.writeObject(p.get(x));
}

} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally{
try{
fichero.close();
}catch(IOException f){}

}

}