Hello Friend,

Try the following code:

import java.util.*;

class MatchString{
    public static void accept(String st1,String st2){
        int count=0;
        char ch1[]=st1.toCharArray();
        Stack<Character> stack1=new Stack<Character>();
        Stack<Character> stack2=new Stack<Character>();
        char ch2[]=st2.toCharArray();
        for(int i=0;i<ch1.length;i++){
            stack1.push(Character.valueOf(ch1[i]));
        }
        for(int i=0;i<ch2.length;i++){
            stack2.push(Character.valueOf(ch2[i]));
        }
        for(int i=0;i<stack2.size();i++){
            if(stack1.contains(stack2.get(i))){
                count++;
            }
        }
        System.out.println("No of matches: "+count);
    }
    public static void main(String[] args){
        String st1="abcdefg";
        Scanner input=new Scanner(System.in);
        System.out.println("Enter string: ");
        String st2=input.next();
        String con="";
        accept(st1,st2);
        do{
        System.out.println("Would you like to check other string? yes or no?");
        con=input.next();
        if(con.equals("yes")){
        System.out.println("Enter string: ");
        String st=input.next();
            accept(st1,st);
        }
        else{
            System.exit(0);
        }
        }
        while(!con.equals("No"));
        }
}

Thanks