Main.java

package org.example;


import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;

public class Main {

    public static File createFileFromUserInput() {
        File file = new File("data.txt");
        try (Scanner userInput = new Scanner(System.in)) {
            FileWriter writer = new FileWriter("data.txt", true);
            if (file.createNewFile()) {
                System.out.println("Dokumenti u krijua: " + file.getName());
                System.out.println("Shkruaj cfare ka data.txt: ");
                writer.write(userInput.nextLine());
                writer.close();
            } else {
                System.out.println("Dokumenti ekziston.");
                System.out.println("Shkruaj cfare do ti shtosh dokumentit data.txt: ");
                writer.append("\n").append(userInput.nextLine()).append("\n");
                writer.close();
            }

        } catch (Exception e) {
            System.out.println("An error occurred.");
            e.printStackTrace();
        }
        return file;
    }

    public static void readFile(File file) {
        try (Scanner fileScanner = new Scanner(file)) {
            System.out.println("Teksti i dokumentit data.txt: \n");
            while (fileScanner.hasNextLine()) {
                String text = fileScanner.nextLine();
                System.out.println(text);
            }
        } catch (Exception e) {
            System.out.println("An error occurred.");
            e.printStackTrace();
        }
    }

    public static void countFileLines(File file) {
        try (Scanner fileScanner = new Scanner(file)) {
            int lineCount = 0;
            while (fileScanner.hasNextLine()) {
                lineCount++;
                fileScanner.nextLine();
            }
            System.out.println("Dokumenti ka " + lineCount + (lineCount == 1 ? " rresht." : " rreshta."));
        } catch (Exception e) {
            System.out.println("An error occurred.");
            throw new RuntimeException(e);
        }
    }

    public static void divider(int numeruesi, int emeruesi) {
        try {
            if (numeruesi == 0 || emeruesi == 0) {
                throw new ArithmeticException("Error, " + (numeruesi == 0 ? "numeruesi" : "emeruesi") + " nuk mund te jete 0. ");
            }
            double result = (double) numeruesi / emeruesi;
            System.out.println(numeruesi + " pjesetim me " + emeruesi + " eshte " + result);
        } catch (ArithmeticException e) {
            System.out.println("Nuk mund te pjesetosh me 0!" + e);
        }
    }

    public static void validateNumber(int number) {
        try {
            if (number < 20) {
                throw new IllegalArgumentException("Numri eshte me i vogel se 20!");
            }
            System.out.println(number + " eshte numer i vlefshem.");
        } catch (IllegalArgumentException e) {
            System.out.println("Numri " + number + " nuk eshte i vlefshem! " + e);
        }
    }

    public static void main(String[] args) {
        //Ushtrimi 1, 2 dhe 3
        System.out.println("Krijimi, leximi dhe numerimi i rreshtave ne dokumentin data.txt:");
        File file = createFileFromUserInput();
        readFile(file);
        countFileLines(file);

        //Ushtrimi 4, 5
        System.out.println("\nMetoda per pjesetimin e numrave. ");
        divider(0, 0);
        divider(2, 4);
        System.out.println("\nMetoda per vleresimin e numrit. ");
        validateNumber(10);
        validateNumber(20);

        //Programi FileManipulator
        System.out.println("\nProgrami FileManipulator ");
        FileManipulator test1 = new FileManipulator("data.txt", 10);
        test1.manipulate();

    }

}