Find Duplicate Characters In a String

public class DuplicateCharacters {    
     public static void main(String[] args) {    
        String string1 = "Great responsibility";    
        int count;    
            
        //Converts given string into character array    
        char string[] = string1.toCharArray();    
            
        System.out.println("Duplicate characters in a given string: ");    
        //Counts each character present in the string    
        for(int i = 0; i  1 && string[i] != '0')    
                System.out.println(string[i]);    
        }    
    }    
}