Reading a binay file (2 - GIF) Learn programming Java

Lesson:

File Management


Exercise:

Reading a binay file (2 - GIF) 30


Objetive:

Create a java program to check if a GIF image file seems to be correct.

It must see if the first four bytes are G, I, F, 8.

In case it seems correct, it must also display the GIF version (87 or 89), checking if the following byte is a 7 or a 9.


Code:

public class Main
{
    public static void main(String[] args)
	{
		byte[] data = new byte[5];
		BinaryReader file = new BinaryReader(File.Open("test.gif", FileMode.Open));

		for (int i = 0; i < 5; i++)
		{
			data[i] = file.ReadByte();
		}

		file.Close();

		if (data[0] == (byte)'G' && data[1] == (byte)'I' && data[2] == (byte)'F' && data[3] == (byte)'8')
		{
			System.out.println("Its a GIF8" + data[4]);
		}
		else
		{
			System.out.println("It not gif file");
		}
	}
}