List Operations

import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Collectors;

public class ListOperations {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        List<Integer> numbers = Arrays
                .stream(scanner.nextLine().split(" "))
                .map(Integer::parseInt)
                .collect(Collectors.toList());

        String command = scanner.nextLine();
        while (!command.equals("End")) {

            String[] commandData = command.split("\\s+");

            String type = commandData[0];

            switch (type) {
                case "Add":
                    int numberAdd = Integer.parseInt(commandData[1]);
                    numbers.add(numberAdd);
                    break;
                case "Insert":
                    int numberInsert = Integer.parseInt(commandData[1]);
                    int insertIndex = Integer.parseInt(commandData[2]);
                    if (isValidIndex(insertIndex, numbers.size())) {
                        numbers.add(insertIndex, numberInsert);
                    } else {
                        System.out.println("Invalid index");
                    }
                    break;
                case "Remove":
                    int removeIndex = Integer.parseInt(commandData[1]);
                    if (isValidIndex(removeIndex, numbers.size())) {
                        numbers.remove(removeIndex);
                    } else {
                        System.out.println("Invalid index");
                    }
                    break;
                case "Shift":
                    String shiftType = commandData[1];
                    int count = Integer.parseInt(commandData[2]);
                    if (shiftType.equals("left")) {
                        shiftLeft(numbers, count);
                    } else if (shiftType.equals("right")) {
                        shiftRight(numbers, count);
                    }
                    break;
            }
            command = scanner.nextLine();
        }
        for (int number : numbers) {
            System.out.print(number + " ");
        }
    }

    private static void shiftRight(List<Integer> numbers, int count) {
        for (int i = 0; i < count; i++) {
            int lastElement = numbers.get(numbers.size() - 1);
            numbers.add(0, lastElement);
            numbers.remove(numbers.size() - 1);
        }
    }

    private static void shiftLeft(List<Integer> numbers, int count) {
        for (int i = 0; i < count; i++) {
            int firstNumber = numbers.get(0);
            numbers.add(firstNumber);
            numbers.remove(0);
        }
    }

    private static boolean isValidIndex(int index, int size) {

        return index >= 0 && index <= size - 1;
    }
}