javascript - Un authorized transaction as the transaction already initiated -

i have completed payment gateway integration on web , want same integration on mobile app, getting said error "un authorized transaction transaction initiated." while getting response, unable handle session or there issue in code. please me close.

**package com.payzak.epos;

import android.app.activity; import android.app.alertdialog; import android.content.dialoginterface; import android.content.intent; import android.graphics.bitmap; import android.net.http.sslerror; import android.os.bundle; import android.util.log; import android.webkit.cookiemanager; import android.webkit.cookiesyncmanager; import android.webkit.sslerrorhandler; import android.webkit.webview; import android.webkit.webviewclient;  /**  * created nivedha on 4/1/2017.  */  public class activity_pg extends activity {  public static string weburl,sessionid;  @override public void oncreate(bundle savedinstancestate){ super.oncreate(savedinstancestate); setcontentview(r.layout.activity_pay_old);  intent in = getintent(); weburl = in.getextras().getstring("url"); //sessionid = in.getextras().getstring("sessionid");  webview pgwebview = (webview)findviewbyid(r.id.pgwebview); pgwebview.getsettings().setjavascriptenabled(true); pgwebview.getsettings().setjavascriptcanopenwindowsautomatically(true);   cookiesyncmanager cookiesyncmanager = cookiesyncmanager.createinstance(pgwebview.getcontext()); cookiemanager cookiemanager = cookiemanager.getinstance(); cookiemanager.setacceptcookie(true); cookiemanager.removesessioncookie(); //cookiemanager.setcookie("https://securepgtest.fssnet.co.in:443/pgway/", sessionid); cookiesyncmanager.sync(); pgwebview.setwebviewclient(new appwebviewclients()); pgwebview.loadurl(weburl);     }  public class mywebviewclient extends webviewclient {         @override public boolean shouldoverrideurlloading(webview view, string url) { view.loadurl(url);             return true;         }     }      public class appwebviewclients extends webviewclient {          public boolean shouldoverrideurlloading(webview view, string url) {              log.d("tag", "shouldoverrideurlloading");             log.d("tag", "actualurl: " + weburl);             log.d("tag", "newurl: " + url);              view.loadurl(url);              return true;          }          @override         public void onpagestarted(webview view, string url, bitmap favicon) {             super.onpagestarted(view, url, favicon);             //show loading if isnt visible             log.d("tag", "onpagestarted");         }          public void onpagefinished(webview view, string url) {          }          public void onreceivederror(webview view, int errorcode, string description, string failingurl) {              log.d("tag", "error description: " + description);             log.d("tag", "failingurl: " + failingurl);         }          @override         public void onreceivedsslerror(webview view, final sslerrorhandler handler, sslerror error) {             try{                 final alertdialog.builder builder = new alertdialog.builder(activity_pg.this);                 builder.setmessage("notification_error_ssl_cert_invalid");                 builder.setpositivebutton("continue", new dialoginterface.onclicklistener() {                     @override                     public void onclick(dialoginterface dialog, int which) {                         handler.proceed();                     }                 });                 builder.setnegativebutton("cancel", new dialoginterface.onclicklistener() {                     @override                     public void onclick(dialoginterface dialog, int which) {                         handler.cancel();                     }                 });                 final alertdialog dialog = builder.create();                 dialog.show();             }catch (exception e){                 e.printstacktrace();             }         }     }  }