java - NullPointer Exception while setting custom listview adapter -

i have been searching around few hours solve problem can't find anything. getting nullpointerexception in line listview.setadapter(adapter);

xml :

 <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical">  <listview xmlns:android="http://schemas.android.com/apk/res/android"     android:id="@+id/list"     android:layout_width="fill_parent"     android:layout_height="wrap_content" />    </linearlayout> 

offlineactivity :

  public class offlineactivity extends activity implements onitemclicklistener   {   string[] filename;   string[] name; list<rowitem> rowitems; string[] dis; listview listview; bufferedreader br; inputstream in; string line; file file; @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     file f = new file(environment.getexternalstoragedirectory()+"/android/data/com.example.test/database/");     f.mkdirs();     filename = f.list();     string[] nametemp = new string[filename.length + 1];     string[] distemp = new string[filename.length + 1];     if(filename[0] == null){         setcontentview(r.layout.empty);     }     else{         setcontentview(r.layout.offline);         try{             for(int i=0; i<filename.length; i++){                 file = new file(environment.getexternalstoragedirectory().tostring()+"/android/data/com.example.test/database/"+filename[i]);                 in = new fileinputstream(file);                 br = new bufferedreader(new inputstreamreader(in));                 nametemp[i] = br.readline();                 line = br.readline();                 distemp[i] = br.readline();             }      }catch(filenotfoundexception e){} catch(ioexception e){}         name = nametemp;         dis = distemp;         setcontentview(r.layout.empty);         rowitems = new arraylist<rowitem>();         (int = 0; < name.length; i++) {             if(name[i]==null) break;             rowitem item = new rowitem(name[i], dis[i]);             rowitems.add(item);         }         listview = (listview) findviewbyid(r.id.list);         customlistviewadapter adapter = new customlistviewadapter(this, r.layout.list_item, rowitems);         listview.setadapter(adapter);         listview.setonitemclicklistener(this);     } }    @override public void onitemclick(adapterview<?> parent, view view, int position, long id) {     toast.maketext(this, "loading lyrics "+name[position]+"...", toast.length_short).show();     intent = new intent(this, showdataactivity.class);     i.putextra("name", name[position]);     i.putextra("filename", filename[position]);     startactivity(i);  }   } 

this code customlistviewadapter class :

 public class customlistviewadapter extends arrayadapter<rowitem> { context context; public customlistviewadapter(context context, int resourceid, list<rowitem> items) {     super(context, resourceid, items);     this.context = context; } /*private view holder class*/ private class viewholder {     textview txttitle;     textview txtdesc; } public view getview(int position, view convertview, viewgroup parent) {     viewholder holder = null;     rowitem rowitem = getitem(position);     layoutinflater minflater = (layoutinflater) context         .getsystemservice(activity.layout_inflater_service);     if (convertview == null) {         convertview = minflater.inflate(r.layout.list_item, null);         holder = new viewholder();         holder.txtdesc = (textview) convertview.findviewbyid(r.id.desc);         holder.txttitle = (textview) convertview.findviewbyid(r.id.title);         convertview.settag(holder);     } else         holder = (viewholder) convertview.gettag();     holder.txtdesc.settext(rowitem.getdesc());     holder.txttitle.settext(rowitem.gettitle());     return convertview; }   } 

here's code rowitem class:

 public class rowitem { private string title; private string desc; public rowitem( string title, string desc) {     this.title = title;     this.desc = desc; } public string getdesc() {     return desc; } public void setdesc(string desc) {     this.desc = desc; } public string gettitle() {     return title; } public void settitle(string title) {     this.title = title; } @override public string tostring() {     return title + "\n" + desc; }  } 

this logcat :

  e/androidruntime(20534): java.lang.runtimeexception: unable start activity componentinfo{com.example.test/com.example.test.offlineactivity}: java.lang.nullpointerexception   e/androidruntime(20534):  @ com.example.test.offlineactivity.oncreate(offlineactivity.java:59)   w/activitymanager(22626):   force finishing activity com.example.test/.offlineactivity 

my 59th line : listview.setadapter(adapter);

any solve appreciated

correct me if i'm wrong looks calling

setcontentview(r.layout.empty); 

again before try initialize listview. assuming r.layout.empty doesn't contain listview id of list return null when try initialize listview.

for reasons this, idea call setcontentview() more once in same activity. there better way, imho.