需要在request中设置相应的属性才能在页面接收到

public class AllServlet extends HttpServlet {

    String title = "title...";

    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setAttribute("title", title);
        request.getRequestDispatcher("/themes/tuzuan/all.jsp").forward(request, response);
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {



    }

}