import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

public class ByteArrayOutputStreamDemo
{

    public static void main(String[] args) throws IOException
    {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();

        System.out.println("Enter the chars:");
        while (byteArrayOutputStream.size() != 4)
        {
            // Gets the inputs from the user
            byteArrayOutputStream.write(System.in.read());
        }

        byte[] byteArray = byteArrayOutputStream.toByteArray();
        
        System.out.println("\nPrint the content");
        for (int x = 0; x < byteArray.length; x++)
        {
            // printing the characters
            System.out.print((char) byteArray[x] + "   ");
        }
        System.out.println("   \n");

        int c;

        ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(byteArray);

        System.out.println("Converting characters to Upper case ");
        for (int y = 0; y < 1; y++)
        {
            while ((c = byteArrayInputStream.read()) != -1)
            {
                System.out.print(Character.toUpperCase((char) c)
                        + "   ");
            }
        }
    }

}