find the duplicate characters in a string.

public class DuplicateCharacters {
          
          public static void main(String[] args) {
                   // TODO Auto-generated method stub
                  String str = new String("Sakkett");
                  int count = 0;
                  char[] chars = str.toCharArray();
                  System.out.println("Duplicate characters are:");
                  for (int i=0; i<str.length();i++) {
                              for(int j=i+1; j<str.length();j++) {
                                         if (chars[i] == chars[j]) {
                                                    System.out.println(chars[j]);
                                                    count++;
                                                    break;
                                          }
                               }
                   }
           }
 
}