Lab 4.4 (Java)

import java.util.Scanner;
import java.io.*;


public class Main {
    public static Scanner scanner = new Scanner(System.in);
    public static Scanner fileScanner;
    public static final int MAX = 50;
    public static void main(String[] args) throws IOException {
        control();
    }

    public static void control() throws IOException {
        String path;
        String str;
        if (selectToOpen() == 1) {
            path = getPath();
            fileScanner = new Scanner(path);
            str = getStrFromFile(path);
        } else {
            str = getLine();
        }
        String newStr = recur(str);
        if (selectToSave() == 1) {
            path = getPath();
            outputToFile(newStr, path);
        } else {
            outputToConsole(newStr);
        }
        scanner.close();
    }

    public static String getLine() {
        String str = "";
        boolean isCorrect;
        System.out.println("Enter line:");
        do {
            isCorrect = true;
            try {
                str = scanner.nextLine();
            } catch (Exception e) {
                isCorrect = false;
            }
            if (isCorrect & (str.length() > MAX)) {
                isCorrect = false;
                System.out.println("Max length = " + MAX);
            }
            if (isCorrect) {
                for (int i = 0; i < str.length(); i++) {
                    if ((str.charAt(i) == 'a') || (str.charAt(i) == 'b') || (str.charAt(i) == 'c') || (str.charAt(i) == 'A') || (str.charAt(i) == 'B') || (str.charAt(i) == 'C')) {
                    } else {
                        isCorrect = false;
                    }
                }
                if (!isCorrect) {
                    System.out.println("Only A, B and C can be entered");
                }
            }
        } while (!isCorrect);
        return str;
    }

    public static String recur(String text) {
        text = text.replace("baba", "ba");
        text = text.replace("BABA", "BA");
        int p = text.indexOf("baba");
        int q = text.indexOf("BABA");
        if(p < 0 & q < 0)
            return text;
        else
            return recur(text);
    }

    static int selectToOpen () {
        int choice = 0;
        boolean isCorrect;
        do {
            System.out.println("If you want to read data from a file - enter 1, from the console - enter 0");
            isCorrect = true;
            try {
                choice = Integer.parseInt(scanner.nextLine());
            } catch (Exception e) {
                isCorrect = false;
                System.out.println("Check the correctness of the entered data");
            }
            if (isCorrect && (choice != 1 && choice != 0)) {
                isCorrect = false;
                System.out.println("Enter 1 or 0");
            }
        } while (!isCorrect);
        return choice;
    }

    static int selectToSave () {
        int choice = 0;
        boolean isCorrect;
        do {
            System.out.println("If you want to write data to a file - enter 1, if not - enter 0");
            isCorrect = true;
            try {
                choice = Integer.parseInt(scanner.nextLine());
            } catch (Exception e) {
                isCorrect = false;
                System.out.println("Check the correctness of the entered data");
            }
            if (isCorrect && (choice != 1 && choice != 0)) {
                isCorrect = false;
                System.out.println("Enter 1 or 0");
            }
        } while (!isCorrect);
        return choice;
    }

    public static String getPath () {
        boolean isCorrect;
        String path;
        do {
            isCorrect = true;
            System.out.println("Enter the full path to the file");
            path = scanner.nextLine();
            File file = new File(path);
            if (!file.exists()) {
                isCorrect = false;
                System.out.println("check the correctness of the entered directory");
            }
        } while (!isCorrect);
        return path;
    }

    public static String getStrFromFile (String path) {
        String str = "";
        boolean isCorrect;
        do {
            isCorrect = true;
            try {
                Scanner fileReader = new Scanner(new File(path));
                str = fileReader.nextLine();
            } catch (Exception e) {
                isCorrect = false;
                System.out.println("Check the correctness of the data in the file");
                path = getPath();
            }
            if (isCorrect && str.length() > MAX) {
                isCorrect = false;
                System.out.println("check the correctness of the data in the file");
                path = getPath();
            }
        } while (!isCorrect);
        return str;
    }

    public static void outputToFile(String res, String path) throws IOException {
        FileWriter writer = new FileWriter(path);
        writer.write("New line = " + res);
        writer.close();
        System.out.println("Data saved successfully");
    }

    public static void outputToConsole(String res) {
        System.out.println("New line: " + res);
    }
}