Project with file operation

 /// Lost it :)

import java.io.FileWriter;
import java.util.HashMap;
import java.util.Scanner;

class Subject {
    String name;
    double cgpa;
    int credit;

    HashMap<String, Object> toMap() {
        HashMap<String, Object> map = new HashMap<>();
        map.put("name", name);
        map.put("cgpa", cgpa);
        map.put("credit", credit);

        return map;
    }

    static Subject scan(Scanner sc) {
        Subject subject = new Subject();

        System.out.print("Enter subject name: ");
        subject.name = sc.nextLine();

        System.out.print("Enter cgpa: ");
        subject.cgpa = sc.nextDouble();

        System.out.print("Enter credit: ");
        subject.credit = sc.nextInt();

        return subject;
    }

    void save() throws Exception {
        FileWriter writer = new FileWriter(name + ".txt");
        writer.write(toMap().toString());
        writer.close();
    }

}

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);

        Subject subject = Subject.scan(sc);
        subject.save();

        System.out.println(subject.toMap());

        sc.close();
    }
}