Given a String return true if any permutation of the String is palindrome

isPalinDrome

public static boolean isPalinDrome(String str){
        if(str==null || str.length()==0){
            throw new IllegalArgumentException("Invalid words");
        }else{
            str = str.trim();
            char[] array = str.toCharArray();
            Set<Character> sets = new HashSet<>();
            for(char ch:array){
                boolean add = sets.add(ch);
                if(!add){
                    sets.remove(ch);
                }
            }
            return sets.size()<=1;
        }

    }