private String readLine() {
		String line = null;
		do {
			if (this.currentThread.isInterrupted()) {
				this.log.info("MessageReceiver thread is Interrupted");
				finishFileReceiverThread();
				return null;
			}
			try {
				if (this.inputMessageReceiver.ready())
					line = this.inputMessageReceiver.readLine();
				else
					line = null;
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
				line = null;
				this.log.info("readLine from inputMessageReceiver: fail");
			}
		} while (line == null);
		return line;
	}