File and I/O

package belajar.io;

import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Scanner;

public class FileIO
{

    private static Scanner scan;

    public static void main(String[] args) throws IOException, ClassNotFoundException
    {
        File file = new File("test.txt");

        //Write your name and age to the file

//      try
//      {
//          PrintWriter output = new PrintWriter(file);
//          output.println("Rahmad Nasution ");
//          output.println(24);
//
//          output.close();
//      } catch (IOException ex) {
//          System.out.printf("EROR : %s\n", ex);
//      }
//
//      // Reads from the file
//      try {
//          scan = new Scanner(file);
//          String name = scan.nextLine();
//          int umur = scan.nextInt();
//
//          System.out.printf("Name : %s\nUmur : %d\n",name, umur);
//      } catch (FileNotFoundException ex) {
//          System.out.printf("ERROR : %s/n",ex);
//      }

        File file1 = new File("students.txt");
        ArrayList<Student> students = new ArrayList<Student>();
        students.add(new Student("Rahmad",3.921));
        students.add(new Student("Rahmadi", 4.0));
        students.add(new Student("Andari", 2.0));
        //serialize the collection of student
        FileOutputStream fo = new FileOutputStream(file1);
        ObjectOutputStream output1 = new ObjectOutputStream(fo);
        for(Student s : students)
        {
            output1.writeObject(s);
        }

        output1.close();
        fo.close();
        //deserelize the file back into the collection
        FileInputStream fi = new FileInputStream(file1);
        ObjectInputStream input1 = new ObjectInputStream(fi);

        ArrayList<Student> students2 = new ArrayList<Student>();
        try {
            while (true)
            {
                Student s1 = (Student)input1.readObject();
                students2.add(s1);
            }

        } catch (EOFException ex) {
            // TODO: handle exception
        }
        for(Student s : students2)
        {
            System.out.println(s);
        }

    }

}

import java.io.Serializable;

public class Student implements Serializable{
    private String Name;
    private double GPA;

    public Student(String name, double gpa) {
        this.Name = name;
        this.GPA = gpa;
    }

    public String getName() {
        return this.Name;
    }

    public String setName(String newname) {
        return (this.Name = newname);
    }

    public double getGPA() {
        return this.GPA;
    }

    public double setGPA(double newGPA) {
        return (this.GPA = newGPA);
    }

    @Override
    public String toString()
    {
        return String.format("%s\t%f", this.Name, this.GPA);
    }

}