io StudentDataStream 28-10-2019

package club.iostream;

import club.model.Student;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.time.LocalDate;

public class StudentDataStream {

    public static void writeStudentData (String fileName, Student[] students) {
        try (FileOutputStream fos = new FileOutputStream (fileName);
            DataOutputStream dos = new DataOutputStream(fos)) {
            for (int i=0; i<students.length; i++) {
                Student student = students[i];
                dos.writeLong(student.getStudentId());
                dos.writeUTF(student.getStudentName());
            }
        } catch (IOException ex) {
            System.out.println(ex.getMessage());
        }

    }

    public static void readStudentData (String fileName) {
        try (FileInputStream fis = new FileInputStream(fileName);
            DataInputStream dis = new DataInputStream(fis)) {
            while (dis.available()!=0){
                long readId = dis.readLong();
                String readName = dis.readUTF();
                System.out.println("Id: " + readId + ", " + "Name: " + readName);
            }
        } catch (IOException ex) {
            System.out.println(ex.getMessage());

        }
    }

    public static Student[] genStudent(int size) {
        Student genStudent[] = new Student[size];
        for (int i=0; i<size; i++) {
            long id = 61100+((int)(Math.random()*99) +1);
            int ch1 = ((int) (Math.random() * (90-65+1))) + 65;
            int ch2 = ((int) (Math.random() * (90-65+1))) + 65;
            int ch3 = ((int) (Math.random() * (90-65+1))) + 65;
            String name = "S" + (char)ch1 + (char)ch2 + (char)ch3;
            genStudent[i] = new Student(id,name);
        }
        return genStudent;
    }

    public static void printStudentList(Student[] stdList) {
        for (int i=0; i<stdList.length; i++) {
            System.out.println(stdList[i]);
        }
    }


    public static void main(String[] args) {
       Student[] studentList = genStudent(10);
       printStudentList(studentList);
       writeStudentData("studentlist" + "-" + LocalDate.now()+".dat",studentList);
       readStudentData("studentlist-2019-10-28.dat");
    }

}