PhoneBook

package fileWork.PhoneBook;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;

public class Phone {
    public String ownerName;
    public String lineNumber;
    public int lastPay;
    private final int startPay = -1;

    public Phone(String lineNumber, String ownerName) {
        this.ownerName = ownerName;
        this.lineNumber = lineNumber;
        this.lastPay = startPay;
    }

    public Phone(Scanner scan) {
        this.lineNumber = scan.next();
        this.ownerName = scan.next();
        this.lastPay = scan.nextInt();
    }

    public Phone(String fileName) throws FileNotFoundException {
        Scanner scan = new Scanner(new File(fileName));
        this.lineNumber = scan.next();
        this.ownerName = scan.next();
        this.lastPay = scan.nextInt();
    }

    public void save(PrintWriter pw) throws FileNotFoundException {
        pw.print(this.lineNumber + " " + this.ownerName + " " + this.lastPay);
        pw.println();
    }

    public void save(String fileName) throws FileNotFoundException {
        PrintWriter pw = new PrintWriter(new File(fileName));
        pw.print(this.lineNumber + " " + this.ownerName + " " + this.lastPay);
        pw.close();
    }

    @Override
    public String toString() {
        return "LineNumber=" + lineNumber + '\n' +
                "ownerName=" + ownerName + '\n' +
                "lastPay=" + lastPay + '\n';
    }
}

================================================================================================

package fileWork.PhoneBook;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Scanner;

public class PhoneBook {
    public String ownerName;
    public Phone[] numbers;
    public int numsAmount;

    public PhoneBook(String ownerName, int maxAmount) {
        this.ownerName = ownerName;
        this.numbers = new Phone[maxAmount];
        numsAmount = 0;
    }

    public PhoneBook(String fileName) throws FileNotFoundException {
        Scanner scan = new Scanner(new File(fileName));
        if (scan.hasNextLine()) {
            this.ownerName = scan.nextLine();
        }
        if (scan.hasNextLine()) {
            this.numbers = new Phone[Integer.parseInt(scan.nextLine())];
        }
        if (scan.hasNextLine()) {
            this.numsAmount = Integer.parseInt(scan.nextLine());
        }
        for (int i = 0; i < numsAmount; i += 1) {
            numbers[i] = new Phone(scan);
            //To make it just for
            if (scan.hasNextLine()) {
                scan.nextLine();
            }
        }
    }

    public void add(Phone phone) {
        this.numbers[numsAmount] = phone;
        numsAmount += 1;
    }

    public void save(String fileName) throws FileNotFoundException {
        PrintWriter pw = new PrintWriter(new File(fileName));
        pw.println(ownerName);
        pw.println(this.numbers.length);
        pw.println(this.numsAmount);
        for (int i = 0; i < this.numsAmount; i += 1) {
            numbers[i].save(pw);
        }
        pw.close();
    }

    @Override
    public String toString() {
        String res = "PhoneBook\n" +
                "ownerName=" + ownerName + '\n' +
                "numsAmount=" + numsAmount + '\n' +
                "numbers: \n";
        for (int i=0; i<numbers.length; i+=1) {
            if(numbers[i]!=null) {
                res += numbers[i].toString();
            }
        }
        return res;
    }
}


====================================================================================================

package fileWork;

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


public class main {
    public static void main(String[] args) throws IOException {
        Phone p1 = new Phone("0546764039", "Misha");
        Phone p2 = new Phone("0501234567", "Bob");
        Phone p3 = new Phone("0529876573", "Lolo");
        File f = new File("C:\\Users\\goodi\\IdeaProjects\\DataBaseWorking\\src\\res\\nums.txt");

        /*For 7 a-d
        PrintWriter pw = new PrintWriter(f);
        p1.save(pw);
        p2.save(pw);
        p3.save(pw);
        pw.close();
        fileToPrint(f);
        */

        //For targil 13
        PhoneBook pb1 = new PhoneBook("Misha",20);
        pb1.add(p1);
        pb1.add(p2);
        pb1.add(p3);
        pb1.save("nums.txt");

        PhoneBook pb2 = new PhoneBook("nums.txt");
        System.out.println(pb2.toString());
    }

    //Help function to write a file into console
    public static void fileToPrint(File f) throws FileNotFoundException {
        Scanner scan = new Scanner(f);
        while(scan.hasNextLine()){
            System.out.println(scan.nextLine());
        }
    }

}