Course

/*
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 * and open the template in the editor.
 */
package ass;

/**
 *
 * @author NgT
 */
import java.io.*;
import java.util.*;

public class Ass {

    public void listAllStudent() {
        File file = new File("D:\\Assignment.std");

        ArrayList<Student> std = new ArrayList<>();
        int count = 0;
        std = readAll(file);
        for (Student s : std) {
            count++;
            System.out.println(count + ".ID: " + s.getId() + " Name: " + s.getName() + " Score: " + s.getScore());

        }
    }

    public void addNewStudent() {

        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter Student Id: ");
        int Id = Integer.parseInt(scanner.nextLine());
        System.out.println("Enter Student name: ");
        String name = scanner.nextLine();
        System.out.println("Enter Student score: ");
        float score = Float.parseFloat(scanner.nextLine());
        Student student = new Student(Id, name, score);

        String std = student.getId() + "|" + student.getName() + "|" + student.getScore() + "\r\n";

        try {
            String filename = "D:\\Ass.std";
            File file = new File(filename);
            RandomAccessFile raf = new RandomAccessFile(file, "rw");

            raf.seek(raf.length());

            raf.writeBytes(std);

            raf.close();

        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }

    public ArrayList<Student> readAll(File n) {
        ArrayList arrStudent = new ArrayList();
        try {
            RandomAccessFile file = new RandomAccessFile(n, "r");
            String r = "";
            while ((r = file.readLine()) != null) {
                Student std = new Student();
                String[] str = r.split("\\|");
                std.setId(Integer.parseInt(str[0].toString()));
                std.setName(str[1].toString());
                std.setScore(Float.parseFloat(str[2].toString()));
                arrStudent.add(std);
            }
            file.close();
        } catch (IOException | NumberFormatException ex) {
            System.out.println(ex.getMessage());
        }
        return arrStudent;
    }

    public void searchID() {
        System.out.println("Input student Id: ");
        Scanner sc = new Scanner(System.in);
        int id = Integer.parseInt(sc.nextLine());
        File file = new File("D:\\Ass.std");

        ArrayList<Student> std = new ArrayList<>();
        boolean se = true;
        std = readAll(file);
        for (Student s : std) {
            if (id == s.getId()) {
                System.out.println("ID: " + s.getId() + "\nName: " + s.getName() + "\nScore: " + s.getScore());
                se = false;
                break;
            }
        }
        if (se) {
            System.out.println("Student not found!!");
        }
    }

    public void removeID() {
        System.out.println("Input student Id: ");
        Scanner sc = new Scanner(System.in);
        int id = Integer.parseInt(sc.nextLine());
        File file = new File("D:\\Ass.std");

        ArrayList<Student> std = new ArrayList<>();
        boolean rm = false;

        for (Student s : std) {
            if (id == s.getId()) {
                int choice;
                System.out.println("Are you sure deleting this student? (1.Yes  2.No");
                choice = new Scanner(System.in).nextInt();
                if (choice == 1) {
                    std.remove(s);
                }
                rm = true;
            }
        }
        if (rm == false) {
            System.out.println("Can not find student with id ");
        }
    }

    public void displayAd() {

        System.out.println("1. Add new students");
        System.out.println("2. Search for student based on his/her id");
        System.out.println("3. List all of the students");
        System.out.println("4. Delete student based on student id");
        System.out.println("Choose option: ");
        String input;
        Scanner scan = new Scanner(System.in);
        input = scan.nextLine();
        switch (input) {
            case "1":
                addNewStudent();
                break;
            case "2":
                searchID();
                break;
            case "3":
                listAllStudent();
                break;
            case "4":
                removeID();
                break;
            default:
                break;
        }

    }

    public static void main(String[] args) {
        // TODO code application logic here
        Ass ass = new Ass();
        ass.displayAd();
    }

}