handler.java

    public AbstractHandler getHandler() {
        return new AbstractHandler() {
            @Override
            public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
                if (request.getPathInfo().equals(route + "/nextCommand")) {
                    String nextCommand;
                    synchronized (elevator) {
                        nextCommand = elevator.nextCommand();
                    }
                    response.getWriter().print(nextCommand);
                    response.getWriter().flush();
                    response.getWriter().close();
                }
            }
        };
    }