FileHandler.java

import java.io.*;
import java.util.*;

public class FileHandler {
    private static final String FILE_NAME = "students.txt";

    public static void saveToFile(List<Student> students) {
        try (BufferedWriter writer = new BufferedWriter(new FileWriter(FILE_NAME))) {
            for (Student s : students) {
                writer.write(s.getId() + "," + s.getName() + "," + s.getAge() + "," + s.getCourse() + "," + s.getMarks());
                writer.newLine();
            }
        } catch (IOException e) {
            System.out.println("Error saving data: " + e.getMessage());
        }
    }

    public static List<Student> loadFromFile() {
        List<Student> students = new ArrayList<>();

        try (BufferedReader reader = new BufferedReader(new FileReader(FILE_NAME))) {
            String line;
            while ((line = reader.readLine()) != null) {
                String[] parts = line.split(",");
                if (parts.length == 5) {
                    String id = parts[0].trim();
                    String name = parts[1].trim();
                    int age = Integer.parseInt(parts[2].trim());
                    String course = parts[3].trim();
                    double marks = Double.parseDouble(parts[4].trim());
                    students.add(new Student(id, name, age, course, marks));
                }
            }
        } catch (FileNotFoundException e) {
            // File doesn't exist yet; no students to load
        } catch (IOException e) {
            System.out.println("Error loading data: " + e.getMessage());
        }

        return students;
    }
}