Tygodniowe Wyzwanie Programistyczne - zadanie #1 dla początkujących (rozwiązanie)

Sandwich.java

package com.pietras.service;


import java.util.Arrays;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

public class Sandwich {


    public static final String CHLEB = "chleb";

    public static String getSandwichUsingRegexp(String input){
        Matcher matcher = Pattern.compile("chleb(.*)chleb").matcher(input);
        if (matcher.find()) {
            return matcher.group(1);
        }
        return "";
    }

    public static String getSandwichUsingIndexOf(String input) {
        int firstIndex = input.indexOf(CHLEB);
        int lastIndex = input.lastIndexOf(CHLEB);
        if (firstIndex < lastIndex) {
            return input.substring(firstIndex + CHLEB.length(), lastIndex);
        }
        return "";
    }

    public static  String getSandwichUsingSplit(String input){
       String[] ingredients =input.split(CHLEB,-2);
        if(ingredients.length>=3) {
            String[] ingredientsInside = Arrays.copyOfRange(ingredients, 1, ingredients.length - 1);
            return Arrays.stream(ingredientsInside).collect(Collectors.joining(CHLEB));
        }
        return "";
    }
}