import java.io.RandomAccessFile;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
		    		
public class CreateFile{
	public static void main(String[] args) throws Exception {
		RandomAccessFile out = new RandomAccessFile("test.txt", "rw");
		FileChannel fc = out.getChannel();
		int length = 0x8FFFFFF;
		MappedByteBuffer MappByteBuff = fc.map(FileChannel.MapMode.READ_WRITE,
				0, length);
		for (int i = 0; i < length; i++)
		{
			MappByteBuff.put((byte) 'B');
		}
		System.out.println("File successFully written");
	}
}