Input Stack Size 5000 Latex Whats Wrong With My Code? It Throws An Array Index Out Of Bounds Exception?

Whats wrong with my code? It throws an array index out of bounds exception? - input stack size 5000 latex

Input string;
Scanner console = System.in (new);
Stack stack = new Stack ();

System.out.println ( "Enter a mathematical expression:");
console.nextLine entry = ();

StringTokenizer st = new input (StringTokenizer, "");
char [] token = st.nextToken (). toString (). toCharArray ();
int count = 0;
int sum = 0;
this int i = 0;
int prod = 0;
quo int i = 0;
while (st.hasMoreTokens ()) (
if (Character.isDigit (tokens [count])) (/ / throw an exception on this route
stack.push (tokens [count]);
count + +;
)
else (
if (st.nextToken (). ("+")) equals (
sum = Integer.parseInt (stack.Pop (). toString ()) + Integer.parseInt (stack.Pop (). toString ()) ...
stack.push (sum);
)
else if (st.nextToken (). equals ("-")) (
diff = Integer.parseInt (stack.Pop (). toString ()) + Integer.parseInt (stack.Pop (). toString ()) ...
stack.push (diff);
)
else if (st.nextToken (). ("*")) equals (
prod = Integer.parseInt (stack.Pop (). toString ()) + Integer.parseInt (stack.Pop (). toString ()) ...
stack.push (total);
)
else if (st.nextToken (). ("/")) equals (
quo = Integer.parseInt (stack.Pop (). toString ()) + Integer.parseInt (stack.Pop (). toString ()) ...
stack.push (quo);
)
else if (stack.size () == 1) (
System.out.println (stack.Pop ());
)
)
)