import java.io.*;
import java.util.Scanner;

public class ReadWrite {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        try {
            RandomAccessFile rand = new RandomAccessFile("C:/Users/Caiden/Desktop/Stu.dat", "rw");
            for (int i=0;i<5;i++) {
                System.out.print("Student ID:");
                rand.writeInt(scan.nextInt());
                System.out.print("GPA:");
                rand.writeDouble(scan.nextDouble());
            }
            boolean terminate = false;
            while (!terminate) {
                System.out.println("Type ID to see GPA. Type 0 to exit.");
                int id = scan.nextInt();
                if (id == 0) {
                    terminate = true;
                    break;
                }
                rand.seek(0);
                int curr = 0;
                while (curr != -1 && curr != id) {
                    if (rand.getFilePointer() != rand.length())
                        curr = rand.readInt();
                    else break;
                }
                if (curr == id) System.out.println("GPA: " + rand.readDouble());
                else System.out.println("Sorry! ID not found!");
            }
        } catch (IOException e) {
            System.out.println("IO error!");
            e.printStackTrace();
        } finally {
            System.out.println("Shutting down...");
        }
    }
}