Secret Chat [Java]

import java.util.Scanner;

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

        String message = scan.nextLine();

        String input = scan.nextLine();

        while (!input.equals("Reveal")) {
            String[] token = input.split(":\\|:");
            String command = token[0];

            switch (command) {
                case "InsertSpace": {
                    int index = Integer.parseInt(token[1]);

                    message = message.substring(0, index).concat(" ").concat(message.substring(index));

                    System.out.println(message);
                    break;
                }
                case "Reverse": {
                    String substring = token[1];
                    StringBuilder newSubstring = new StringBuilder(substring);

                    if (message.contains(substring)) {
                        substring = newSubstring.reverse().toString();

                        int startIndex = message.indexOf(token[1]);
                        int endIndex = startIndex + token[1].length();

                        StringBuilder updatedString = new StringBuilder(message);

                        updatedString.delete(startIndex, endIndex);
                        message = updatedString.append(substring).toString();

                        System.out.println(message);
                    } else {
                        System.out.println("error");
                    }

                    break;
                }
                case "ChangeAll": {
                    String substringChange = token[1];
                    String replacement = token[2];

                    message = message.replace(substringChange, replacement);

                    System.out.println(message);
                    break;
                }
            }

            input = scan.nextLine();
        }

        System.out.println("You have a new text message: " + message);
    }
}