How to open a txt file and read numbers in Java

Question

How can I open a .txt file and read numbers separated by enters or spaces into an array list?

Answer 1

A much shorter alternative is below:

Path filePath = Paths.get("file.txt");
Scanner scanner = new Scanner(filePath);
List integers = new ArrayList<>();
while (scanner.hasNext()) {
    if (scanner.hasNextInt()) {
        integers.add(scanner.nextInt());
    } else {
        scanner.next();
    }
}

A Scanner breaks its input into tokens using a delimiter pattern, which by default matches whitespace. Although default delimiter is whitespace, it successfully found all integers separated by new line character.