Java implementation of Infix to Postfix

import java.util.Scanner;

public class InFixToPostFix

{

    int Priority(char TopSym,char Sym)

    {

        if(TopSym=='(')

            return 0;

        if(Sym=='(')

            return 0;

        if(Sym==')')

            return 1;

        if((TopSym=='*'||TopSym=='/'))

            return 1;

        if((TopSym== '+'||TopSym=='-')&&(Sym=='-'||Sym=='+'))

            return 1;

        if((TopSym== '+'||TopSym=='-')&&(Sym=='*'||Sym=='/'))

            return 0;

        else

            return 1;

    }

    boolean isOperand(char Sym)

    {

        if(Sym>='0'&& Sym<='9')

            return true;

        else

            return false;

    }

    void Convert(char infix[],char postfix[])

    {

        Stack_Char sc=new Stack_Char();

        int inpos,und=1,outpos=0;

        char TopSym='+',Sym;

        for(inpos=0;inpos<infix.length;inpos++)

        {

            Sym=infix[inpos];

            if(isOperand(Sym))

                postfix[outpos++]=Sym;

            else

            {

                if (sc.isEmpty()==true)

                    und=1;

                else

                {

                    und=0;

                    TopSym=(char)sc.Pop();

                }

                while(und==0 && Priority(TopSym,Sym)==1)

                {

                    postfix[outpos++]=TopSym;

                        if (sc.isEmpty()==true)

                            und=1;

                        else

                        {

                            und=0;

                            TopSym=(char)sc.Pop();

                        }

                }

                if(und==0)

                    sc.Push(TopSym);

                if(und==1||(Sym!=')'))

                    sc.Push(Sym);

                else

                    TopSym=(char)sc.Pop();

            }

        }

        while(sc.isEmpty()==false)

            postfix[outpos++]=(char)sc.Pop();

    }

    public static void main(String args[])

    {

        Scanner in = new Scanner(System.in);

        InFixToPostFix i=new InFixToPostFix();

        String Infix;

        char postfix[]=new char[30];

        System.out.println("Enter Infix Equation");

        Infix=in.nextLine();

        i.Convert(Infix.toCharArray(), postfix);

        System.out.print("Postfix Expression = ");

        System.out.println(postfix);

    }

}