Can you complete this code for me please below is the requirement.

Create a stack based program StackMath that accepts a user's infix or postfix expression string and displays it in the other notation along with an evaluation of this expression $($hint: see textbook sections $5\mathrm{.}16,5\mathrm{.}18$ and $5\mathrm{.}21).$ Also necessary is StackInterface.

Your program will contain the following methods, which may be in separate classes:

infix$2$postfix $$ converts infix to postfix

postfix$2$infix $$ converts postfix to infix

evaluatePostfix $$ evaluates the postfix expression $($using a stack$)$

evaluateInfix $$ evaluates the postfix expression $($using a stack$)$

Have your program allow the user to optionally use the classes:

LinkedStack, as outlined in Listing $6-1$

ArrayStack, as outlined in Listing $6-2$

Each of the above classes include these ancillary methods, at least:

pop

push

peek

isEmpty

clear

Within LinkedStack's comments, explain if toArray is should be included. Include it if so$.$

Within ArrayStack's comments, explain if toArray is should be included. Include it if so$.$

Program displays correct infix expression of user's postfix expression.

Program displays correct postfix expression of user's infix expression.

Program properly evaluates user's infix expression, displaying the correct result.

Program properly evaluates user's postfix expression, displaying the correct result.

Here is my code which I almost finish it$.$

import java.util.Scanner;

public class StackMath $\{$

public static void main$($String$[]$ args$)\{$

Scanner scanner $=$ new Scanner$($System$.$in$)$;

System.out.println$("$Enter an expression $($infix or postfix$)$:$")$;

String expression $=$ scanner.nextLine$()$;

StackInterface stack;

System.out.println$("$Choose stack implementation: $(1)$ LinkedStack $(2)$ ArrayStack"$)$;

int choice $=$ scanner.nextInt$()$;

scanner.nextLine$()$; $//$ Consume newline

if $($choice $==1)\{$

stack $=$ new LinkedStack$<>()$;

$\}$ else if $($choice $==2)\{$

stack $=$ new ArrayStack$<>()$;

$\}$ else $\{$

System.out.println$("$Invalid choice. Exiting program."$)$;

return;

$\}$

if $($isInfix$($expression$))\{$

String postfix $=$ infixToPostfix$($expression$)$;

System.out.println$("$Postfix expression: $"+$ postfix$)$;

System.out.println$("$Evaluation: $"+$ evaluatePostfix$($postfix$,$ stack$))$;

$\}$ else $\{$

String infix $=$ postfixToInfix$($expression$)$;

System.out.println$("$Infix expression: $"+$ infix$)$;

System.out.println$("$Evaluation: $"+$ evaluateInfix$($infix$,$ stack$))$;

$\}$

$\}$

public static boolean isInfix$($String expression$)\{$

$//$ Simple heuristic to determine if the expression is infix or postfix

return expression.contains$("+")||$ expression.contains$("-")||$ expression.contains$("*")||$ expression.contains$("/")$;

$\}$

public static String infixToPostfix$($String infix$)\{$

$//$ Implement infix to postfix conversion

$//$ You can use the StackInterface here

return $""$;

$\}$

public static String postfixToInfix$($String postfix$)\{$

$//$ Implement postfix to infix conversion

$//$ You can use the StackInterface here

return $""$;

$\}$

public static int evaluatePostfix$($String postfix, StackInterface stack$)\{$

$//$ Implement postfix expression evaluation

$//$ You can use the StackInterface here

return $0$;

$\}$

public static int evaluateInfix$($String infix, StackInterface stack$)\{$

$//$ Implement infix expression evaluation

$//$ You can use the StackInterface here

return $0$;

$\}$

$\}$

interface StackInterface $\{$

void push$($T element$)$;

T pop$()$;

T peek$()$;

boolean isEmpty$()$;

void clear$()$;

$\}$

class LinkedStack implements StackInterface $\{$

$//$ Implementation of LinkedStack

$\}$

class ArrayStack implements StackInterface $\{$

$//$ Implementation of ArrayStack

$\}$

just do the implementations and fix if there mistakes thanks