response.sendRedirect（）不会重定向，不会引发任何错误

Question

I try to develop a voice controlled web application. The problem is that it is not redirecting to the existing Webservlets url and does not shown any error messages. Here is my doPost method in my Controller.java file: (in the second 'if' the redirect works fine, only in the third is not working.)

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
    HttpSession session = req.getSession();

    if (req.getParameter("productId") != null){
        int prodID = Integer.parseInt(req.getParameter("productId"));
        cartHandler.add(prodID);
    }
    // LOGOUT
    if(req.getParameter("btn-logout") != null){
        if(session.getAttribute("uID") != null) {
            session.removeAttribute("uID");
            resp.sendRedirect("/");
        }
    }

    if(req.getParameter("allieStart") != null){
        String greeting = allieDaoJDBC.getAnswer("greeting");
        playSound.play(greeting);
        Integer react = speechRecognition.listen(allieDaoJDBC, cartHandler);
        if(react == 1){
            resp.sendRedirect("/cart");
        }else if(react == 2){
            resp.sendRedirect("/login");
        }
    }
}

Thank you guys in advance!

Answer 1

If you are sure allieStart is not null, then the problem must be with react (ie react is not 1 or 2.) Try adding another else condition, so you can be sure something will happen.

    if(react == 1){
        resp.sendRedirect("/cart");
    }else if(react == 2){
        resp.sendRedirect("/login");
    }else{
        resp.sendRedirect("/login");
    }