marvk

public final class Groupify {
    public static String groupify(final String input, final int groupSize) {
        if (groupSize < 1) {
            throw new IllegalArgumentException("groupSize must be bigger than zero, was " + groupSize);
        }

        final String inputPadded = input + "x".repeat((groupSize - input.length() % groupSize) % groupSize);

        final String[] split = inputPadded.split("(?<=\\G.{" + groupSize + "})");

marvk

public final class Caesar {
    private static final int NUM_LETTERS = 26;

    public static String caesar(final String s, final int shift) {
        return s.chars()
                .filter(Caesar::isEnglishLetter)
                .map(character -> getIntUnaryOperator((char) character, shift))
                .collect(StringBuilder::new, StringBuilder::appendCodePoint, StringBuilder::append)
                .toString();
    }

marvk

So, whats wrong with the following start to a constructor of a Graph class?

public Graph(String fileName) {
    File file = null;
    try {
        file = new File(fileName);
    } catch (Exception e) {
        // TODO: handle exception
 }