java - Updating dynamically jsp page in browser after POST http request -


i have following project: backend written in java; main class creates listener on log file, retrieves info when log modified, , creates object called "candidate", , send of attributes servlet via post method. works until here, , 200 response code servlet.

then, created frontend (with bootstrap such looks nice) in index.jsp file, consist of static part (background, messages, logos, etc.) , dynamic part, want update each time log file modified. simplified version of index.jsp can found below, in firstname example of data should arrive post request:

<%@ page language="java" contenttype="text/html; charset=iso-8859-1"     pageencoding="iso-8859-1"%> <!doctype html public "-//w3c//dtd html 4.01 transitional//en" "http://www.w3.org/tr/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=iso-8859-1"> <!-- if ie use latest rendering engine --> <meta http-equiv="x-ua-compatible" content="ie=edge">  <!-- set page width of device , set zoon level --> <meta name="viewport" content="width = device-width, initial-scale = 1">  <title>user page</title>  <style>  @import url('bootstrap/css/bootstrap.css');       </style> <script type=”text/javascript” src=”bootstrap/js/bootstrap.min.js”></script> </head> <body style="background-image:url(images/xxxx.jpg); background-size:cover; " >   <% string firstname = (string) request.getparameter("firstname"); %>  <div class="container"> <div class="page-header"> <h1 style="color:white">hello   <%if(firstname != null){%>      <%=firstname %> <%}%> welcome new page.</h1>  </div> <img src="images/xx.png" style="width:35%;height:35%; padding-left: 10%; padding-top:10%"/> </div> </body> </html>

my ultimate goal user sees index.jsp page, updates of content data "new candidate" each time log modified.

to run application, have several run instances. run main class, , on top of that, run index.jsp , myservlet on server. right way run it?

because when that, , modify log, main class console prints everything, showing post request has been sent (i have tried send request servlet or directly jsp file) no request received index.jsp (or @ least doesnt display in browser opened in eclipse), after refreshing page.

what work, however, when modify manually url in browser add url query parameter ?firstname=xxxx , refresh, message included in index.jsp page. how can make sure sent post request through backend dynamically modifies index.jsp page?

last note: when log file modified, console prints system.out.println corresponding first name seen below in doget method, how assumed works there.

here servlet code:

package com.xyz.xxxxx;  import java.io.ioexception; import java.io.printwriter;  import javax.servlet.servletcontext; import javax.servlet.servletexception; import javax.servlet.annotation.webservlet; import javax.servlet.http.httpservlet; import javax.servlet.http.httpservletrequest; import javax.servlet.http.httpservletresponse; import javax.servlet.http.httpsession;  /**  * servlet implementation class myservlet  */ @webservlet("/myservlet") public class myservlet extends httpservlet {     private static final long serialversionuid = 1l;      /**      * @see httpservlet#dopost(httpservletrequest request, httpservletresponse response)      */     protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {         //response.setintheader("refresh", 5);          response.setcontenttype("text/html");         printwriter writer = response.getwriter();         string firstname = request.getparameter("firstname");         system.out.println("testing get: first name : " + firstname);             // forward request jsp page          request.getrequestdispatcher("/web-inf/index.jsp").forward(request,response);      }     protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {          doget(request,response);     }   }

and file organization here.

thank !

i'm going take leap of faith here , assume looking persist values of firstname post

this require adjust code quite bit, don't want provide implementation if classroom project.

from code snippet you've provided: looks trying achieve following:

  1. get -> display index.html name supplied post
  2. post -> change name given session.

therefore, should accessing page using whatever defined on servletclass.

once understand httpsession, should desired effect


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