JSP在第一次访问时执行doPost

Question

我用一个表单制作了JSP页面。用户可以写评论，它将以POST方式发送。 servlet将它存储在数据存储区中并列出所有注释并将其转发给jsp，jsp会将它们放在一个表中。问题是在第一次访问中没有任何东西会存在，因为doPOst没有被调用！这是我的代码

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

        // INSERT CODE HERE

        System.out.println("received HTTP POST");
        String postContent = request.getParameter("post_text");
        System.out.println(postContent);
         Date date= new Date();
      Timestamp timeStamp=  new Timestamp(date.getTime());
     long lonTime= timeStamp.getTime();

            DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();       
            Entity post = new Entity("post");
            post.setProperty("content", postContent);

            post.setProperty("time", lonTime); 
            datastore.put(post);
        System.out.println(    post.getKey()   );

        int pageSize = 20;
        FetchOptions fetchOptions = FetchOptions.Builder.withLimit(pageSize);

        Query q = new Query("post").addSort("time", SortDirection.DESCENDING);
        PreparedQuery pq = datastore.prepare(q);

        QueryResultList<Entity> results = pq.asQueryResultList(fetchOptions);
        System.out.println("-------------------");
        for (Entity entity : results) {

 System.out.println(entity.getProperty ("content"));
 System.out.println(entity.getProperty ("time"));
        }

        request.setAttribute("postList",results);
        String strViewPage="/tublr.jsp";
        RequestDispatcher dispatcher = request.getRequestDispatcher(strViewPage);
        if (dispatcher != null){
                dispatcher.forward(request, response);
        } ;