Java 8 # Get second Unique Char form String "swiss"

 import java.util.*;

import java.util.stream.*;
public class UniqueChar
{
    public static void main(String a[])
    {
        String str = "swiss";
        String result = String.valueOf(str.chars().mapToObj(c -> (char)c)
                .collect(Collectors.groupingBy(c ->c, LinkedHashMap::new, Collectors.counting()))
                .entrySet()
                .stream()
                .filter( e -> e.getValue() ==1)
                        .map(Map.Entry::getKey)
                .findFirst()
                .orElse(null));

        System.out.println("Final Result >>>" +result);
    }
}