Programa de estructura de datos (ejecutable java)

/**
*
* @author Filiberto Flores Arenas
*/

import java.io.*;
import java.util.*;
public class Main {

/**
* @param args the command line arguments
*///Declaracion de Variables
static int a[];
static int n,m,i=-1,c=0,vi=-1,j,valor;

public static void main(String[] args)
{

// TODO code application logic hereInputStreamReader leer=new InputStreamReader(System.in);
BufferedReader dato=new BufferedReader (leer);

System.out.print("Introduce el tamaño del arreglo: ");
try{
n=Integer.parseInt(dato.readLine());
}
catch(Exception e){}
a=new int[n];
do{System.out.println("\n·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·");
System.out.println("***************(Estructura De Datos)***************");
System.out.println("·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·");System.out.println("1.-Ir a Menu Pila");
System.out.println("2.-Ir a Menu Cola");
System.out.println("3.-Ir a Menu Vector");
System.out.println("4.-Salir");System.out.println("\n···················································\n");
System.out.print("Introduce una Opción: ");


try
{m=Integer.parseInt(dato.readLine());
}
catch(Exception e){}

switch(m)
{
case 1:
Formatear();
do
{System.out.println("\n·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·");
System.out.println("********************(Menu Pila)********************");System.out.println("·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·~·");
System.out.println("1.-Introducir");
System.out.println("2.-Extraer ");
System.out.println("3.-Regresar ");...