android - Rss reader with custom array adapter -

i'm making android app rss feed in android studio , i'm trying put title , description from: http://feeds.bbci.co.uk/news/rss.xml, 2 textviews using custom adapter. rss feed in tab. , each time try run program exception , problem occurs in class:

    public class ladapter extends arrayadapter<info> {     public ladapter(context context, arraylist<info> nfos) {super(context, 0,nfos);}      @override     public view getview(int position, view convertview, viewgroup parent) {         // data item position         info info = getitem(position);         // check if existing view being reused, otherwise inflate view         if (convertview == null) {             convertview = layoutinflater.from(getcontext()).inflate(r.layout.basic_list_item, parent, false);         }         // lookup view data population         textview title = (textview) convertview.findviewbyid(r.id.tit);         textview description = (textview) convertview.findviewbyid(r.id.desc);          title.settext(info.title);         description.settext(info.description);          // return completed view render on screen         return convertview;     } } 

partial tab_1.class:

public class tab_1 extends fragment { listview mlist; arraylist<info> arrayofinfo; ladapter adapter;  @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.tab_1, container, false);     ladapter adapter = new ladapter(getactivity(), arrayofinfo); #line 44->  mlist = (listview) v.findviewbyid(r.id.list);     new getrssfeed().execute("http://feeds.bbci.co.uk/news/rss.xml");     mlist.setadapter(adapter);     return v; } 

exception:

process: com.example.pauly.myapplication, pid: 3896 java.lang.nullpointerexception: attempt invoke interface method 'int java.util.list.size()' on null object reference         @ android.widget.arrayadapter.getcount(arrayadapter.java:330)         @ android.widget.listview.setadapter(listview.java:487)         @ com.example.pauly.myapplication.tabs.tab_1.oncreateview(tab_1.java:43)         @ android.support.v4.app.fragment.performcreateview(fragment.java:1789)         @ android.support.v4.app.fragmentmanagerimpl.movetostate(fragmentmanager.java:955)         @ android.support.v4.app.fragmentmanagerimpl.movetostate(fragmentmanager.java:1138)         @ android.support.v4.app.backstackrecord.run(backstackrecord.java:740)         @ android.support.v4.app.fragmentmanagerimpl.execpendingactions(fragmentmanager.java:1501)         @ android.support.v4.app.fragmentmanagerimpl.executependingtransactions(fragmentmanager.java:490)         @   android.support.v4.app.fragmentstatepageradapter.finishupdate(fragmentstatepageradapter.java:163)             @ android.support.v4.view.viewpager.populate(viewpager.java:1072)             @ android.support.v4.view.viewpager.populate(viewpager.java:918)             @ android.support.v4.view.viewpager.onmeasure(viewpager.java:1440) ... 

ladapter adapter = new ladapter(getactivity(), arrayofinfo); 

arrayofinfo null (it's not initialized), because call asynctask after arrayofinfo. data receive doinbackground method, can set arrayofinfo data in method onpostexecute in asynctask , after array set data, can call in onpostexecute

ladapter adapter = new ladapter(getactivity(), arrayofinfo); mlist.setadapter(adapter); 

onpostexecute handling ui.