Simulink keyboard as an output problem

Hello, I would like to use keyboard as output in Simulink, I'm trying to use Matlab Function Block, Java Robot Class and coder.extrinsic to declare extrinsic function but when I start the simulation I get an error: "Import statements are currently unsupported". The program code looks like

function y = fcn(u)
coder.extrinsic('import');
import java.awt.*;
import java.awt.event.*;
rob=Robot;
rob.keyPress(KeyEvent.VK_A)
rob.keyRelease(KeyEvent.VK_A)
y = u;

Is there an opportunity to solve this problem? I use Matlab version 2016a.

Thanks in advance !