последний пункт

while (reader.ready()){
    data = reader.readLine();
    mas = data.split(",");

arrList.add(data.split("\\p{Punct}"));

for (String[] mas : arrList) { // перебираем строки
        for (int i = 0; i < mas.length; i++) { // перебираем слова в строках.
            if (mas[i].equals("world")){
                count++;
            }
        }
}

public class Solution {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String fileName = reader.readLine();

        reader = new BufferedReader(new FileReader(fileName));
        String data;
        List<String[]> list = new ArrayList<>();
        int count = 0;
        while (reader.ready()){
            data = reader.readLine();
            list.add(data.split("\\p{Punct}"));
        }
        reader.close();

        for (String[] mas: list) {
            for (int i = 0; i < mas.length; i++) {
                if (mas[i].equals("world")){
                    count++;
                }
            }
        }
        System.out.println(count);
    }
}

reader = new BufferedReader(new FileReader(fileName));

while (reader.ready()) {
    data = reader.readLine();

while ((data = reader.readLine()) != null) {

.split("\\W");