java - populating alert dialog with list view,JSON -

i trying fill alert dialog son response how ever getting following error :

java.lang.nullpointerexception: attempt invoke virtual method 'void android.widget.listview.setadapter(android.widget.listadapter)' on null object reference

i have inflated list view in oncreate other posts suggest

i have included relevant xml , java code

<?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:orientation="horizontal" >     <checkedtextview         android:id="@+id/text1"         android:layout_width="match_parent"         android:layout_height="?listpreferreditemheightsmall"         android:checkmark="?android:attr/listchoiceindicatorsingle"         android:gravity="center_vertical"         android:paddingleft="?listpreferreditempaddingleft"         android:paddingright="?listpreferreditempaddingright"         android:textappearance="?textappearancelistitemsmall" />  </linearlayout>  <?xml version="1.0" encoding="utf-8"?> <relativelayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:orientation="vertical"     android:background="@color/colorprimary"     tools:context=".queue.queuestatusfragment">     <listview         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:id="@+id/listviewresp"         android:paddingleft="@dimen/activity_horizontal_margin"         android:paddingtop="15dp"         android:layout_centervertical="true"         android:layout_alignparentstart="true" /> </relativelayout>  public class queuestatusfragment extends fragment{      arraylist<hashmap<string, string>> oslist = new arraylist<hashmap<string, string>>();      private textview txtqueue;     private textview txtcust;     private textview txttime;     private textview txtbranch;     private string urlstring;     private button btnleave;     private int reasonid;     listview list;     public queuestatusfragment()     {}      @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);     }      @override     public view oncreateview(layoutinflater inflater, viewgroup container,                              bundle savedinstancestate) {         view v = inflater.inflate(r.layout.fragment_queuestatus, container, false);        txtqueue = (textview) v.findviewbyid(r.id.txtqueue);         txttime = (textview) v.findviewbyid(r.id.txttime);        txtcust = (textview) v.findviewbyid(r.id.txtcust);         txtbranch = (textview) v.findviewbyid(r.id.txtbranch);         list=(listview)v.findviewbyid(r.id.listviewresp);         btnleave = (button) v.findviewbyid(r.id.btnleave);         sessionv globalvariable = (sessionv) getactivity().getapplicationcontext();           urlstring = "http://172.20.10.5:1012/easyq.svc/rest/queuedetails/" + globalvariable.getcustid();         new processjson().execute(urlstring);         system.out.println("works");          btnleave.setonclicklistener(new view.onclicklistener() {              @override             public void onclick(view v) {                  alertdialog alertdialog = new alertdialog.builder(                         getactivity()).create();                  alertdialog.settitle("alert");                  alertdialog.setmessage("you leave queue, sure?");                   alertdialog.setbutton("ok", new dialoginterface.onclicklistener() {                     public void onclick(dialoginterface dialog, int which) {                         urlstring = "http://172.20.10.5:1012/easyq.svc/rest/reasons";                         new getreasons().execute(urlstring);                          for(int = 0; < oslist.size();i++)                         {                             string id = oslist.get(i).get("id");                             system.out.println(id);                         }                     }                 });                 alertdialog.show();                // sessionv globalvariable = (sessionv) getactivity().getapplicationcontext();                 //string urlstring1 = "http://172.20.10.5:1012/easyq.svc/rest/leavequeue";                // new jsonhandler().execute(urlstring1);                 //system.out.println("works");             }         });          // inflate layout fragment         return v;     }      @override     public void onattach(activity activity) {         super.onattach(activity);     }      @override     public void ondetach() {         super.ondetach();     }      private class processjson extends asynctask<string, void, string> {         protected string doinbackground(string... strings) {             string stream;             string urlstring = strings[0];             httpdatahandler hh = new httpdatahandler();             stream = hh.gethttpdata(urlstring);             // return data specified url             system.out.println(stream);             return stream;         }          protected void onpostexecute(string stream) {             if (stream != null) {                 string[] array = stream.split(",");                 string part1 = array[1];                 string part2 = array[2];                 string part3 = array[3];                 string part4 = array[4];                 string queueid = array[5];                 sessionv globalvariable = (sessionv) getactivity().getapplicationcontext();                 globalvariable.setqueueid(queueid);                  if (part1 != null && part2 != null && part3 != null) {                     int minutes = (int) integer.parseint(part1) / 60;                     txtbranch.append("branch name: " + part4);                     txtqueue.append("service name: " + part3);                     txtcust.append("queue position: " + part2);                     txttime.append("waiting time: " + minutes + " minutes");                  }             }         }     }      private class getreasons extends asynctask<string, void, string>{         protected string doinbackground(string... strings) {             string stream;             string urlstring = strings[0];             httpdatahandler hh = new httpdatahandler();             stream = hh.gethttpdata(urlstring);             // return data specified url             system.out.println(stream);             return stream;         }          protected void onpostexecute(string stream) {             if (stream != null)             {                try                {                     jsonobject object = new jsonobject(stream);                     jsonarray array = object.getjsonarray("reasonsresult");                     for(int = 0 ; < array.length(); i++) {                        jsonobject reasonobj = array.getjsonobject(i);                        string id = reasonobj.getstring("reason_leaving_id");                        string reason = reasonobj.getstring("description");                         hashmap<string, string> map = new hashmap<string, string>();                        map.put("description", reason);                        map.put("id", id);                        oslist.add(map);                    }                     alertdialog alertdialog = new alertdialog.builder(                            getactivity()).create();                     alertdialog.settitle("alert");                     alertdialog.setmessage("you leave queue, sure?");                    for(int = 0; < oslist.size(); i++)                    {                         listadapter adapter = new simpleadapter(getactivity(), oslist,                                r.layout.dialog_list,                                new string[] { "description"}, new int[] {                                r.id.text1});                         list.setadapter(adapter);                        list.setonitemclicklistener(new adapterview.onitemclicklistener() {                             @override                            public void onitemclick(adapterview<?> parent, view view,                                                    int position, long id) {                                string branchid = oslist.get(+position).get("id");                                final sessionv globalvariable = (sessionv) getactivity().getapplicationcontext();                                globalvariable.setbranchid(branchid);                                  fragment fragment = null;                                fragment = new joinfragment();                                getactivity().getsupportfragmentmanager().begintransaction().replace(r.id.container_body, fragment).commit();                             }                        });                    }                     alertdialog.show();                }                catch(jsonexception e)                {                    e.printstacktrace();                }             }         }     }     private class jsonhandler extends asynctask<string, void, string> {         protected string doinbackground(string... strings) {             string stream;             string urlstring = strings[0];             httpdatahandler hh = new httpdatahandler();             final sessionv globalvariable = (sessionv) getactivity().getapplicationcontext();              system.out.println("sssss" + globalvariable.getqueueid() + globalvariable.getcustid());             jsonobject sender = new jsonobject();             try {                 sender.put("queueid", globalvariable.getqueueid());                 sender.put("customerid", globalvariable.getcustid());                 //sender.put("reasonid",);             } catch (jsonexception e) {                 e.printstacktrace();             }             stream = hh.post(urlstring, sender);             // return data specified url             system.out.println(stream);             return stream;         }          protected void onpostexecute(string stream) {             if (stream != null) {                 if (stream.equals("\"successful\"")) {                     toast.maketext(getactivity().getapplicationcontext(),                             "successfully left queue", toast.length_long).show();                     fragment fragment=null;                     fragment=new homefragment();                     getactivity().getsupportfragmentmanager().begintransaction().replace(r.id.container_body, fragment).commit();                 } else if (stream.equals("\"not exist\"")) {                     toast.maketext(getactivity().getapplicationcontext(),                             "unable leave queue", toast.length_long).show();                 } else if (stream.equals("\"not exist\"")) {                     toast.maketext(getactivity().getapplicationcontext(),                             "not in queue", toast.length_long).show();                 }             }         }     } } <relativelayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="fill_parent"     android:layout_height="fill_parent"     android:background="@color/colorprimary"     tools:context=".queue.queuestatusfragment" >      <textview         android:id="@+id/txtbranch"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_weight="8"         android:layout_centerhorizontal="true"         android:layout_centerinparent="false"         android:text="hello"         android:layout_margintop="100dp"         android:gravity="center|left"         android:textcolor="#ffffff"         android:textcolorhint="#ffffff" />      <textview         android:id="@+id/txtqueue"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_weight="8"         android:text="hello1"         android:layout_margintop="160dp"         android:gravity="center|left"         android:textcolor="#ffffff"         android:layout_centerhorizontal="true"         android:layout_centerinparent="false"         android:textcolorhint="#ffffff" />      <textview         android:id="@+id/txttime"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_weight="8"         android:text="hello2"         android:gravity="center|left"         android:layout_margintop="44dp"         android:layout_centerinparent="false"         android:textcolor="#ffffff"         android:textcolorhint="#ffffff"         android:layout_below="@+id/txtqueue"         android:layout_alignstart="@+id/txtqueue" />      <textview         android:id="@+id/txtcust"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_weight="8"         android:text="hello3"         android:gravity="center|left"         android:textcolor="#ffffff"         android:layout_margintop="47dp"         android:layout_centerinparent="false"         android:textcolorhint="#ffffff"         android:layout_below="@+id/txttime"         android:layout_alignstart="@+id/txttime" />      <button         android:id="@+id/btnleave"         android:layout_width="312dp"         android:layout_height="wrap_content"         android:background="@color/coloraccent"         android:gravity="center"         android:text="leave queue"         android:textcolor="#ffffff"         android:textstyle="bold"         android:layout_marginbottom="65dp"         android:layout_alignparentbottom="true"         android:layout_centerhorizontal="true" /> </relativelayout> 

i think problem in fragment_queuestatus there no listview. add previous layout. why it's not listview , when try set adapter it's thing set in null object. so, add listview in fragment_queuestatus layout. solve problem.