Find out the repeated character in the given string

import java.util.*;
public class MyClass {
    public static void main(String args[]) {
        Scanner s=new Scanner(System.in);
     
       String str=s.nextLine() ;
        ArrayList listStr = new ArrayList();

       for (int i =0; i< str.length(); i++)
       {
           if (listStr.contains(str.charAt(i)))
               System.out.println("Repeated Character Found:"+str.charAt(i));
            else
               listStr.add(str.charAt(i));
         
       }
    }

}
 
input: abbcdeffsah
output:
Repeated Character Found:b
Repeated Character Found:f
Repeated Character Found:a