请求转发 include 就是相当于能拿到 其他界面的数据，可以很好的复用。比如网页的头尾

private void test2(HttpServletRequest request, HttpServletResponse response) {
        try {
             response.setHeader("content-type", "text/html;charset=UTF-8");
             response.setCharacterEncoding("UTF-8");
             request.getRequestDispatcher("/ServletHeader").include(request, response);//引用ServletHeader
             response.getOutputStream().write("This is servletDemo3".getBytes());
             request.getRequestDispatcher("/ServletFooter").include(request, response);//引用ServletFooter
        } catch (Exception e) {
        }    
    }

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
         response.setHeader("content-type", "text/html;charset=UTF-8");
         response.setCharacterEncoding("UTF-8");
         response.getOutputStream().write("This is footer".getBytes());
    }

  
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
         response.setHeader("content-type", "text/html;charset=UTF-8");
         response.setCharacterEncoding("UTF-8");
         response.getOutputStream().write("This is header".getBytes());
    }

就这样 困屎