byte [] image_number_array = int2ByteArray(image_number);
byte [] image_number_array = ArrayManipulator.int2ByteArray(image_number);
    public static byte[] createDownloadDatagram(int file_index, int image_number)    {	//creation	byte datagram[] = UDPDatagramHeader.createUDPDatagramHeader(file_index, Opcode.DOWNLOAD, 10);	byte [] image_number_array = int2ByteArray(image_number);	int i; int shift = UDPDatagramHeader.getHeaderSize();	//initialisation	for(i=0; i<4; i++)	    datagram[i+shift] = image_number_array[i];	return datagram;    }