lab2_4(java)

package com.company;
import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Scanner;
import java.util.regex.PatternSyntaxException;

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

    public static void main(String[] args){
        System.out.println("Welcome to the program that checks is a given sequence of numbers  non-growing");
        byte inputSource = takeSource("entering the sequence of numbers");
        double[] sequence = takeSequence(inputSource);
        String answer = findAnswer(sequence);
        byte outputSource = takeSource("output the answer");
        output(outputSource,answer);
        scan.close();
    }

    static byte takeSource(final String purpose){
        System.out.print("Select the source for " + purpose + ":\n1:Console\n2:File\nEnter 1 or 2: ");
        boolean isIncorrect;
        byte choice = 0;
        final byte CONSOLE = 1;
        final byte FILE = 2;
        do {
            isIncorrect = false;
            try {
                choice = Byte.parseByte(scan.nextLine());
            } catch (Exception e) {
                System.out.print("Incorrect input!!! Select the source for " + purpose + ":\n1:Console\n2:File\nEnter 1 or 2: ");
                isIncorrect = true;
            }
            if (!isIncorrect && (choice != CONSOLE) && (choice != FILE)) {
                System.out.print("Incorrect input!!! Select the source for " + purpose + ":\n1:Console\n2:File\nEnter 1 or 2: ");
                isIncorrect = true;
            }
        } while (isIncorrect);
        return choice;
    }

    static String takeInPath(){
        String path;
        boolean isIncorrect;
        System.out.print("Enter file path: ");
        do {
            isIncorrect = false;
            path = scan.nextLine();
            if (Files.notExists(Path.of(path))) {
                System.out.print("File is not found\nEnter file path: ");
                isIncorrect = true;
            }
            if (!isIncorrect && (!path.endsWith(".txt"))) {
                System.out.print("File is found, but it is not \".txt\" type file\nEnter file path: ");
                isIncorrect = true;
            }
        }while (isIncorrect);
        return path;
    }

    static String takeOutPath(){
        String path;
        boolean isIncorrect;
        System.out.print("Enter file path: ");
        do {
            isIncorrect = false;
            path = scan.nextLine();
            if (!path.endsWith(".txt")) {
                System.out.print("It should be a \".txt\" file\nEnter file path: ");
                isIncorrect = true;
            }
        }while (isIncorrect);
        return path;
    }

    static double[] takeSequenceFromConsole() {
        boolean isIncorrect;
        int size = 0;
        final int MIN_SIZE = 2;
        System.out.print("Enter size: ");
        do {
            isIncorrect = false;
            try {
                size = Integer.parseInt(scan.nextLine());
            } catch (Exception e) {
                System.out.print("Incorrect input!!!\nEnter size: ");
                isIncorrect = true;
            }
            if (!isIncorrect && (size < MIN_SIZE)) {
                System.out.println("The size must be higher than 1\nEnter size: ");
                isIncorrect = true;
            }
        } while (isIncorrect);
        double[] sequence = new double[size];
        for (int i = 0; i < size; i++){
            System.out.print("Enter element " + (i + 1) + ": ");
            do {
                isIncorrect = false;
                try {
                    sequence[i] = Double.parseDouble(scan.nextLine());
                }
                catch(Exception e) {
                    System.out.print("Incorrect input!!!\nEnter element " + (i + 1) + ": ");
                    isIncorrect = true;
                }
            }while (isIncorrect);
        }
        return sequence;
    }

    static double[] takeSequenceFromFile(final String path){
        int size = 0;
        final int MIN_SIZE = 2;
        int lineCounter = 0;
        final int SIZE_LINE_NUMBER = 1;
        final int SEQUENCE_LINE_NUMBER = 2;
        String line;
        String[] stringSequence = null;
        boolean isCorrect = true;
        try {
            BufferedReader reader = new BufferedReader(new FileReader(path));
            while ((isCorrect) && ((line = reader.readLine()) != null)) {
                lineCounter++;
                if (lineCounter == SIZE_LINE_NUMBER){
                    try {
                        size = Integer.parseInt(line);
                    } catch (Exception e) {
                        System.out.println("Incorrect file content!!! Incorrect information in the size line!!!");
                        isCorrect = false;
                    }
                    if (isCorrect && (size < MIN_SIZE)) {
                        System.out.println("Incorrect file content!!! The size must be higher than 1!!!");
                        isCorrect = false;
                    }
                }
                if (lineCounter == SEQUENCE_LINE_NUMBER){
                    try {
                        stringSequence = line.split(" ");
                    } catch (PatternSyntaxException e){
                        System.out.println("Incorrect file content!!! Incorrect information in the sequence line!!!");
                        isCorrect = false;
                    }
                }

            }
            reader.close();
        }catch (IOException e) {
            System.out.println("Input/Output error!!!");
            isCorrect = false;
        }
        double[] sequence = null;
        if ((isCorrect) && ((stringSequence.length != size) || (lineCounter > SEQUENCE_LINE_NUMBER))){
            System.out.println("Incorrect file content!!!");
            isCorrect = false;
        }else{
            sequence = new double[size];
            for (int i = 0;i < size;i++){
                try {
                    sequence[i] = Double.parseDouble(stringSequence[i]);
                } catch (Exception e) {
                    System.out.println("Incorrect file content!!!");
                    isCorrect = false;
                }
            }
        }
        if(isCorrect) {
            System.out.print("Sequence is: ");
            for (int i = 0; i < size; i++) {
                System.out.print(sequence[i] + "; ");
            }
            System.out.println();
            return sequence;
        }else{
            return null;
        }
    }

    static double[] takeSequence(final byte source){
        String inPath;
        double[] sequence;
        if (source == 1) {
            sequence = takeSequenceFromConsole().clone();
        } else {
            inPath = takeInPath();
            sequence = takeSequenceFromFile(inPath);
            while (sequence == null) {
                inPath = takeInPath();
                sequence = takeSequenceFromFile(inPath);
            }
        }
        return sequence;
    }

    static String findAnswer  (final double[] sequence) {
        int i = 0;
        boolean isCorrect;
        do{
            isCorrect = sequence[i] >= sequence[i + 1];
            i++;
        }while ((isCorrect) && (i < sequence.length - 1));
        if (isCorrect) {
            return "The sequence is non-growing";
        }else {
            return "The sequence isn't non-growing";
        }
    }

    static void outputToFile(final String path,final String answer){
        try{
            FileWriter writer = new FileWriter(path);
            writer.write(answer);
            writer.flush();
            System.out.println("Complete!!!");
        }
        catch(IOException ex){
            System.out.println("Incorrect file content!!!");
        }
    }

    static void output(final byte source,final String answer){
        String outPath;
        if (source == 1) {
            System.out.println(answer);
        } else{
            outPath = takeOutPath();
            outputToFile(outPath, answer);
        }
    }
}