Longest substring without repeating chars in Java

import java.util.HashSet;
import java.util.Set;

public class LongestNonrepeatingSubstring {

    public static void main(String[] args) {
        String input = "pwwkew";
        System.out.println(longestNonrepeatingSubstr(input));
    }

    private static int longestNonrepeatingSubstr(String input) {
        int max = 0;
        int count = 0;
        Set<Character> lut = new HashSet<>();

        for (int i = 0; i < input.length(); i++) {
            char currChar = input.charAt(i);

            // Reset counter if needed
            if (lut.contains(currChar)) {
                if (max < count) {
                    max = count;
                }

                count = 0;
                lut = new HashSet<>();
            }

            // Increment counter
            count++;
            lut.add(currChar);
        }

        return max;
    }
}