how to find unique characters in a string in java

1//  I would use linkedHashMap since it doesn't accept
2//  duplicate values
3
4String str = "abbcdddefffggghjilll";
5        String [] arr = str.split("");
6        Map<String, Integer> mapStr = new LinkedHashMap<>();
7
8        for (int i=0 ; i < arr.length ; i++){
9            if (!mapStr.containsKey(arr[i])){
10                mapStr.put(arr[i],1);
11            } else{
12                mapStr.put(arr[i],mapStr.get(arr[i])+1);
13            }
14        }
15
16        for (Map.Entry<String,Integer> map : mapStr.entrySet()) {
17            if(map.getValue()==1) {
18                System.out.print(map.getKey());
19            }
20        }

1public class String_FindtheUnique_4 {
2/* Write a return  method that can find the unique characters from the String
3 Ex:  unique("AAABBBCCCDEF")  ==>  "DEF";  */
4    public static void main(String[] args) {
5
6   String result1 = Unique("BBCCDDSSEEDDYUT");
7   System.out.println(result1); // YUT
8
9//1.yol 
10    String s = "BABABACDR";
11    String r = "";
12    for(String each : s.split(""))
13 r += ( (Collections.frequency(Arrays.asList(s.split("")), each)) ==1 ) ? each : "";
14     System.out.println(r); // CDR
15    }
16
17//2.yol method yolu
18  public static String Unique(String str) {
19        String result1 ="";
20        for(String each : str.split(""))
21result1 += ( (Collections.frequency(Arrays.asList(str.split("")), each)) ==1 ) ? each : "";
22        return result1;
23    }
24
25}
26  

1//  I would use linkedHashMap since it doesn't accept
2//  duplicate values
3
4String str = "abbcdddefffggghjilll";
5        String [] arr = str.split("");
6        Map<String, Integer> mapStr = new LinkedHashMap<>();
7
8        for (int i=0 ; i < arr.length ; i++){
9            if (!mapStr.containsKey(arr[i])){
10                mapStr.put(arr[i],1);
11            } else{
12                mapStr.put(arr[i],mapStr.get(arr[i])+1);
13            }
14        }
15
16        for (Map.Entry<String,Integer> map : mapStr.entrySet()) {
17            if(map.getValue()==1) {
18                System.out.print(map.getKey());
19            }
20        }
21