Create a class called Student. Write a student manager program to manipulate the student information from files by using FileInputStream and FileOutputStream

 
         

import java.io.FileInputStream;
import java.io.FileOutputStream;

public class Student {

    public static void main(String[] args) {
        System.out.println("-------Writing Data in File-------");
        try {
            FileOutputStream fout = new FileOutputStream("stdinfo.txt");
            String str = "Nmae : Sachin, Stream : Computer Engineering, Sem : 5th Sem";
            byte b[] = str.getBytes();
            fout.write(b);
            fout.close();
            System.out.println("successful write.");
        } catch (Exception e) {
            System.out.println(e);
        }
        System.out.println("-------Retrive Data From File-------");
        try {
            FileInputStream fin = new FileInputStream("stdinfo.txt");
            int i = 0;
            while ((i = fin.read()) != -1) {
                System.out.print((char) i);
            }
            fin.close();
        } catch (Exception e) {
            System.out.println(e);
        }
    }
}  
        
  

Write an interactive program to print a diamond shape. For example, if user enters the number 3

import java.util.Scanner;

public class demo {

    public static void main(String[] args) {

        int i, j, k;
        Scanner scan = new Scanner(System.in);
        int no = scan.nextInt();

        for (i = 0; i < no; i++) {

            for (j = (no / 2) + 1; j >= i; j--) {
                System.out.print(" ");
            }

            for (k = 0; k <= i; k++) {
                System.out.print("* ");
            }
            System.out.println();
        }
        for (i = 0; i < no; i++) {
            System.out.print(" ");

            for (j = 0; j <= i; j++) {
                System.out.print(" ");
            }

            for (k = no - 1; k > i; k--) {
                System.out.print("* ");
            }
            System.out.println();
        }

    }
}