android webview only show loaded data after second refresh/load -

i trying write android webview code load data jason file url. however, noticed data not shown on page initial time, succussfully shown if click button load/refresh data page again (not sure if because of refresh or reload). checked log file. first time click output following log.

08-17 16:07:38.784: v/webview(17435):  singlecursorhandlertouchevent -geteditablesupport  fasle  08-17 16:07:39.184: v/webview(17435): doshortpress : mnativeclass - 2089760 mpreventdefault -  2 08-17 16:07:41.777: v/webview(17435):  singlecursorhandlertouchevent -geteditablesupport  fasle  08-17 16:07:42.187: v/webview(17435): doshortpress : mnativeclass - 2089760 mpreventdefault -  2 08-17 16:07:42.588: d/dalvikvm(17435): gc_concurrent freed 375k, 46% free 3455k/6343k, external 377k/1281k, paused 2ms+2ms 

the second time run bring me following text in log, can see loaded string data output log @ last line.

08-17 16:07:51.837: v/webview(17435):  singlecursorhandlertouchevent -geteditablesupport  fasle  08-17 16:07:52.247: v/webview(17435): doshortpress : mnativeclass - 2089760 mpreventdefault -  2 08-17 16:07:55.901: v/webview(17435):  singlecursorhandlertouchevent -geteditablesupport  fasle  08-17 16:07:56.301: v/webview(17435): doshortpress : mnativeclass - 2089760 mpreventdefault -  2 08-17 16:07:56.501: d/dalvikvm(17435): gc_for_malloc freed 117k, 46% free 3472k/6343k, external 377k/1281k, paused 15ms 08-17 16:07:56.501: i/dalvikvm-heap(17435): grow heap (frag case) 6.195mb 87396-byte allocation 08-17 16:07:56.521: d/dalvikvm(17435): gc_for_malloc freed 32k, 46% free 3525k/6471k, external 377k/1281k, paused 16ms 08-17 16:07:56.591: i/my call:(17435): <ul data-role='listview'><li>abc<p style='font-size:1 font-color:grey'>2014-08-11</p></li><li>def<p style='font-size:1 font-color:grey'>2014-08-14</p></li><li>fgh<p style='font-size:1 font-color:grey'>2014-08-14</p></li><li>hijk<p style='font-size:1 font-color:grey'>2014-08-15</p></li></ul> 

can tell why first time didn't bring data? please help. thanks.

following activity code.

@suppresslint("setjavascriptenabled") public class messageactivity extends activity {      webview mwebview;     public static string liststr = "";      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_message);            mwebview = (webview) findviewbyid(r.id.webview);         mwebview.setwebviewclient(new webviewclient() {             public boolean shouldoverrideurlloading(webview view, string url) {                 return false;             }         });         mwebview.setverticalscrollbarenabled(false);         mwebview.getsettings().setjavascriptenabled(true);         mwebview.getsettings().setdomstorageenabled(true);         mwebview.addjavascriptinterface(new javascriptinterface(), "jsinterface");          mwebview.loadurl("file:///android_asset/index.html");     }      public boolean onkeydown(int keycode, keyevent event) {         if ((keycode == keyevent.keycode_back) && mwebview.cangoback()) {             mwebview.destroy();             finish();                     mwebview.destroy();             return true;         }         else if (keycode == keyevent.keycode_back){             mwebview.destroy();             finish();                mwebview.destroy();         }         return super.onkeydown(keycode, event);     }      private class longrunninggetio extends asynctask <void, void, string> {         protected string getasciicontentfromentity(httpentity entity) throws illegalstateexception, ioexception {              inputstream in = entity.getcontent();              stringbuffer out = new stringbuffer();             int n = 1;             while (n>0) {                 byte[] b = new byte[4096];                  n =  in.read(b);                  if (n>0) out.append(new string(b, 0, n));              }              return out.tostring();          }          @override          protected string doinbackground(void... params) {             httpclient httpclient = new defaulthttpclient();             httpcontext localcontext = new basichttpcontext();             httpget httpget = new httpget("http://****/post.json");             string text = null;             try {                  httpresponse response = httpclient.execute(httpget, localcontext);                  httpentity entity = response.getentity();                  text = getasciicontentfromentity(entity);              } catch (exception e) {                 return e.getlocalizedmessage();              }              return text;          }          protected void onpostexecute(string results) {              getjsondata(results);          }          protected void getjsondata (string jsonstr) {             jsonarray postarr = new jsonarray();             liststr = "<ul data-role='listview'>";              try {                 jsonobject posts = (new jsonobject(jsonstr).getjsonobject("posts"));                 postarr = posts.getjsonarray("post");                  (int i=0; i<postarr.length(); i++) {                     jsonobject p = postarr.getjsonobject(i);                     liststr += "<li>";                     liststr += p.getstring("title");                     liststr += "<p style='font-size:1 font-color:grey'>";                     liststr += p.getstring("date");                     liststr += "</p>";                     liststr += "</li>";                 }                 liststr += "</ul>";             } catch (jsonexception e) {                 e.printstacktrace();             }          }      }      public class javascriptinterface {         string str;          @javascriptinterface         public string getpostvalue() {             new longrunninggetio().execute();             this.str = liststr;             return str;         }     } } 

my index.html page.

<!doctype html> <html> <head>     <meta charset="utf-8">     <meta name="viewport" content="width=device-width, initial-scale=1">     <title>loadpagetest</title>     <link rel="stylesheet" href="http://fonts.googleapis.com/css?family=open+sans:300,400,700">     <link rel="stylesheet" href="./css/customizedstyle.css">     <link rel="stylesheet" href="./css/themes/default/jquery.mobile-1.4.3.min.css">     <link rel="stylesheet" href="./css/jqm-demos.css">     <script src="./js/jquery.js"></script>     <script scr="./js/customizedjs.js"></script>     <script src="./js/jquery.mobile-1.4.3.min.js"></script>     <script>         $( document ).on( "pagecreate", "#demo-page", function() {              $( document ).on( "swipeleft swiperight", "#demo-page", function( e ) {                 if ( $( ".ui-page-active" ).jqmdata( "panel" ) !== "open" ) {                     if ( e.type === "swipeleft" ) {                         $( "#right-panel" ).panel( "open" );                     }                  }             });         });         </script>      <style type="text/css">     body {         overflow:hidden;     }     </style> </head> <body style= "overflow:hidden" scrolling="no">  <style type="text/css"> body {     overflow:hidden; } </style>   <div data-role="page" id="main-page" style= "overflow:hidden" scrolling="no">      <div role="main" class="ui-content" id ="maindiv" style= "overflow: auto">          load diff pages here.      </div><!-- /content -->      <div data-role="panel" id="left-panel" data-theme="b">          <ul data-role="listview" data-icon="false" id="menu">              <li>             <a href="#" id = "btna" data-rel="close">go page <img src="./images/icona.png" class="ui-li-thumb"/>             </li>          </ul>      </div><!-- /panel -->       <script type="text/javascript">          $("#btna").on("click", function(){                var listposts = window.jsinterface.getpostvalue();             document.getelementbyid( "maindiv" ).innerhtml = "<html><body>"+listposts+"</body></html>";         });       </script>  </div><!-- /page -->  </body> </html>