Wyjątki kontrolowane i niekontrolowane

package pl.am.errors.lesson4;

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

public class ReadFileOriginal {
    public static void main(String[] args) throws FileNotFoundException {

        Scanner scanner = new Scanner(new File("lista.txt"));
        float sum = 0;
        int number = 0;

        while (scanner.hasNext()) {
            number++;
            String surname = scanner.next();
            int schoolGrade = scanner.nextInt();
            sum += schoolGrade;
            System.out.println(number + " " + surname + ", ocena: " + schoolGrade);
        }

        System.out.println("średnia z matematyki: " + sum/ number);
    }
}

package pl.am.errors.lesson4;

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

public class ReadFile {
    public static void main(String[] args) throws FileNotFoundException {

        Scanner scanner = new Scanner(new File("lista.txt"));
        float sum = 0;
        int number = 0;

        while (scanner.hasNext()) {
            number++;
            Student student = Student.fromFileLine(scanner.nextLine());
            sum += student.getSchoolGrade();
            System.out.println(student);
        }

        System.out.println("średnia z matematyki: " + sum/ number);
    }
}

package pl.am.errors.lesson4;

public class Student {
    private String firstName;
    private String surname;
    private int schoolGrade;

    public Student(String firstName, String surname, int schoolGrade) {
        this.firstName = firstName;
        this.surname = surname;
        this.schoolGrade = schoolGrade;
    }

    public static Student fromFileLine(String fileLine) {
        String[] columns = fileLine.split(" ");
        String firstName = columns[0];
        String surname = columns[1];
        int schoolGrade = Integer.parseInt(columns[1]);

        return new Student(firstName, surname, schoolGrade);
    }

    public String getSurname() {
        return surname;
    }

    public void setSurname(String surname) {
        this.surname = surname;
    }

    public int getSchoolGrade() {
        return schoolGrade;
    }

    public void setSchoolGrade(int schoolGrade) {
        this.schoolGrade = schoolGrade;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    @Override
    public String toString() {
        return "Student{" +
                "firstName='" + firstName + '\'' +
                ", surname='" + surname + '\'' +
                ", schoolGrade=" + schoolGrade +
                '}';
    }
}