/*
 * Creates 20 random integers (1-50) then writes them to a file.
 * Then it reads the file, and outputs them.
 */
import java.util.*;
import java.io.*;
public class Program8
{
    public static void main(String[] args)
    {
        // Create a RNG, and an byte array.
        Random gen = new Random();
        byte[] matrix = new byte[20];
        
        // Creates a file, then has it setup to be removed on exit
        // and creates the actual file.
        File f = new File("data.bin");
        try
        {
            f.deleteOnExit();
            f.createNewFile();
        }
        catch(IOException e)
        {
            System.out.println(e.getMessage());
        }
        try
        {
            // create a file output stream for File f
            FileOutputStream out = new FileOutputStream(f);
            System.out.println("WRITING DATA TO FILE ("+ f.getName() +"):");
            for (int x=0; x<20; x++) 
            {
               // store each integer as a byte
               // then display byte as integer
               matrix[x] = (byte)(1+gen.nextInt(50));
               System.out.print((int)matrix[x] + " ");
            }
            try
            {
                // write out the byte information to the file
                for (int x=0; x<matrix.length;x++)
                {
                    out.write(matrix[x]);
                }
            }
            catch(IOException e)
            {
                System.out.println(e.getMessage());
            }
        }
        catch(FileNotFoundException e)
        {
            System.out.println(e.getMessage());
        }
        System.out.println();
        try
        {
            // create a file input stream for File f
            FileInputStream in = new FileInputStream(f);
            System.out.println("READING DATA FROM FILE ("+ f.getName() +"):");
            try
            {
                for (int x=0;x<20;x++)
                {
                    // read in one byte from file
                    // then display each as integer
                    System.out.print((int)(in.read()) + " ");
                }
            }
            catch(IOException e)
            {
                System.out.println(e.getMessage());
            }
        }
        catch(FileNotFoundException e)
        {
            System.out.println(e.getMessage());
        }
        
    }
}