lab 3.1 java

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

public class Main {
    private static final Scanner scan = new Scanner(System.in);

    public static int choiceCheck() {
        int choice;
        choice = 0;
        boolean isIncorrect;
        do {
            isIncorrect = false;
            try {
                choice = Integer.parseInt(scan.nextLine());
            } catch (Exception err) {
                System.out.println("Error! Input a number");
                isIncorrect = true;
            }
            if (!isIncorrect && (choice < 1 || choice > 2)) {
                System.out.println("Error! Input 1 or 2");
                isIncorrect = true;
            }

        } while (isIncorrect);
        return choice;
    }

    public static String checkInputFilePath() {
        String path;
        boolean isIncorrect;
        do {
            System.out.println("Input path to the file:");
            isIncorrect = false;
            path = scan.nextLine();
            File inputFile = new File(path);
            if (!inputFile.exists()) {
                isIncorrect = true;
                System.out.println("Could not find the file");
            } else if ((!inputFile.canRead()) || (!inputFile.canWrite())) {
                isIncorrect = true;
                System.out.println("Could not open the file");
            }
        } while (isIncorrect);
        return path;
    }

    public static String inputCheck() {
        boolean isIncorrect;
        String str;
        int i;
        System.out.println("Input the string consisting of numbers, letters of the English alphabet and symbols '-', '+', '.'");
        do {
            isIncorrect = false;
            str = scan.nextLine();
            for (i = 0; i < str.length(); i++) {
                if (!((str.charAt(i) == 43) || (str.charAt(i) == 45) || (str.charAt(i) == 46) || ((str.charAt(i) > 47) && (str.charAt(i) < 58)) ||
                        ((str.charAt(i) > 64) && (str.charAt(i) < 91)) || ((str.charAt(i) > 96) && (str.charAt(i) < 123)))) {
                    System.out.println("Incorrect string format");
                    isIncorrect = true;
                }
            }
        }
        while (isIncorrect);
        return str;
    }

    public static String fileCheckString() {
        String path, str, str0;
        boolean isIncorrect;
        int i;
        do {
            isIncorrect = false;
            path = checkInputFilePath();
            File inputFile = new File(path);
            Scanner scan2 = null;
            try {
                scan2 = new Scanner(inputFile);
            } catch (FileNotFoundException e) {
                throw new RuntimeException(e);
            }
            str = scan2.nextLine();
            if ((!isIncorrect) && (str.length() < 1)) {
                isIncorrect = true;
                System.out.println("The string is empty");
            }
            if (scan2.hasNextLine()) {
                isIncorrect = true;
                System.out.println("There should be only one string");
            }
            if (!isIncorrect) {
                for (i = 0; i < str.length(); i++) {
                    if (!((str.charAt(i) == 43 || str.charAt(i) == 45 || str.charAt(i) == 46 || (str.charAt(i) > 47 && str.charAt(i) < 58) ||
                            (str.charAt(i) > 64 && str.charAt(i) < 91) || (str.charAt(i) > 96 && str.charAt(i) < 123))))
                        isIncorrect = true;
                }

            }
            if (isIncorrect) {
                System.out.println("Incorrect string format");
            }
            scan2.close();
        } while (isIncorrect);
        return str;
    }

    public static String inputChoice() {
        int choice;
        String str;
        System.out.println("Choose input option:\n1.Input through console\n2.Input through file");
        choice = choiceCheck();
        if (choice == 1) {
            str = inputCheck();
        } else {
            str = fileCheckString();
        }
        return str;
    }

    public static String checkOutputFilePath() {
        String path;

        System.out.println("Input file path and the name of the file for\nexample С:\\Projects\\Number\\FileName.txt. If the\nfile does not exist, then it will be created\nautomatically in the given directory");
        path = scan.nextLine();
        File outputFile = new File(path);
        if (outputFile.isFile()) {
            if (!outputFile.canRead()) {
                System.out.println("Could not open the file");
            }
        }
        return path;
    }

    public static void findConsoleSubStr(String str) {
        String subStr;
        int i;
        boolean isFound;
        isFound = false;
        subStr = "";
        for (i = 0; i < str.length(); i++) {
            if (str.charAt(i) == '+' || str.charAt(i) == '-') {
                if (subStr.length() > 1) {
                    System.out.println(subStr);
                } else {
                    if ((i > 0) && (str.charAt(i - 1) == '0')) {
                        System.out.println("0");
                    }
                }
                subStr = "";
                subStr += str.charAt(i);
                isFound = true;
            } else {
                if (str.charAt(i) == 46 || (str.charAt(i) > 64 && str.charAt(i) < 91) || (str.charAt(i) > 96 && str.charAt(i) < 123)) {
                    isFound = false;
                    if (subStr.length() > 1) {
                        System.out.println(subStr);
                    } else {
                        if ((i > 0) && (str.charAt(i - 1) == '0')) {
                            System.out.println("0");
                        }
                    }
                    subStr = "";
                } else {
                    if (str.charAt(i) == 48) {
                        if (isFound && !(subStr.charAt(subStr.length() - 1) == '+' || subStr.charAt(subStr.length() - 1) == '-')) {
                            subStr += str.charAt(i);
                        }
                    } else {
                        if (str.charAt(i) > 48 && str.charAt(i) < 58) {
                            if (isFound) {
                                subStr += str.charAt(i);
                            }
                        }
                    }
                }
            }
        }
        if (isFound && subStr.length() > 1) {
            System.out.println(subStr);
        }
    }

    public static void findFileSubStr(String str) {
        String subStr, path;
        int i;
        boolean isFound;
        isFound = false;
        subStr = "";
        path = checkOutputFilePath();
        try (PrintWriter pw = new PrintWriter((path))) {
            for (i = 0; i < str.length(); i++) {
                if (str.charAt(i) == '+' || str.charAt(i) == '-') {
                    if (subStr.length() > 1) {
                        pw.println(subStr);
                    } else {
                        if ((i > 0) && (str.charAt(i - 1) == '0')) {
                            pw.println("0");
                        }
                    }
                    subStr = "";
                    subStr += str.charAt(i);
                    isFound = true;
                } else {
                    if (str.charAt(i) == 46 || (str.charAt(i) > 64 && str.charAt(i) < 91) || (str.charAt(i) > 96 && str.charAt(i) < 123)) {
                        isFound = false;
                        if (subStr.length() > 1) {
                            pw.println(subStr);
                        } else {
                            if ((i > 0) && (str.charAt(i - 1) == '0')) {
                                pw.println("0");
                            }
                        }
                        subStr = "";
                    } else {
                        if (str.charAt(i) == 48) {
                            if (isFound && !(subStr.charAt(subStr.length() - 1) == '+' || subStr.charAt(subStr.length() - 1) == '-')) {
                                subStr += str.charAt(i);
                            }
                        } else {
                            if (str.charAt(i) > 48 && str.charAt(i) < 58) {
                                if (isFound) {
                                    subStr += str.charAt(i);
                                }
                            }
                        }
                    }
                }
            }
            if (isFound && subStr.length() > 1) {
                pw.print(subStr);
            }
        } catch (IOException ex) {
            System.out.println("Unsuccessful output");
        } finally {
            System.out.println("Successful output");
        }
    }

    public static void outputChoice(String str) {
        int choice;
        System.out.println("Choose output option:\n1.Output through console\n2.Output through file");
        choice = choiceCheck();
        if (choice == 1) {
            findConsoleSubStr(str);
        } else {
            findFileSubStr(str);
        }
        scan.close();
    }

    public static void main(String[] args) {
        String str;
        str = inputChoice();
        outputChoice(str);
    }
}