Facturas en java

import java.io.*;
import java.util.*;

public class Factura {



public static void main(String[] args, String String) throws Exception {

Hashtable Numerofactura = new Hashtable();Hashtable Cuentafactura = new Hashtable();


String Lee = "";

String Nombrefactura;
String Factura ;
int Numfactura=1;
int Opcion = 2;

CharSequence Adicionar ;CharSequence Consultar ;
CharSequence Eliminar;
CharSequence Modificar ;


File F1 = new File( "facturas.txt" );
BufferedReader Entrada =new BufferedReader(new FileReader( F1 ));if (F1.exists()){
Lee = Entrada.readLine();
Entrada.close();
StringTokenizer Tok = new StringTokenizer(Lee,";");
while (Tok.hasMoreTokens()){StringTokenizer TokFactura = new StringTokenizer(Tok.nextToken(),",");
Nombrefactura = TokFactura.nextToken();

Nombrefactura = TokFactura.nextToken();
Factura =TokFactura.nextToken();
Numfactura = Integer.valueOf(TokFactura.nextToken());
Adicionar = TokFactura.nextToken();

Numerofactura.put(Factura, Numfactura);Cuentafactura.put(Factura,Nombrefactura);
}
//-------------------------------------------------------------------
InputStreamReader Teclado = new InputStreamReader(System.in);BufferedReader Lectura = new BufferedReader (Teclado);

while (Opcion != 0){
System.out.println("------------------------------------");
System.out.println("******** Menu Principal*********");
System.out.println("******** 1.Adicionar factura *********");
System.out.println("******** 2.Consultar factura *********");
System.out.println("********3.Eliminar factura *********");
System.out.println("******** 0.Cerrar cesion *********");
System.out.println("-----------------------------------------");
Opcion =...