java - Using child method of an Object + ListView + Adapter + Android -

in customized adapter, made heterogeneos arraylist 2 types: playlist , musica. when show them in listview, want show differently. if playlist want show string name of playlist , hifen before name. if musica want show string name. know if item of list playlist or musica, made list save position of playlist items. see code:

private static final int type_playlist = 1; private static final int type_musica = 2; private list<int> posicoesplaylists = new arraylist<>(); private final list<object> items = new arraylist<>();  @override public int getitemviewtype(int position) {     return posicoesplaylists.contains(position) ? type_playlist : type_musica; }  public void setitems(list<playlist> novalista) {     items.clear();     list<musica> musicas;      (playlist playlist: novalista) {         items.add(playlist);         posicoesplaylists.add(items.size() - 1);          musicas = playlist.getmusicas();         (musica musica: musicas) {             items.add(musica);         }     }      notifydatasetchanged(); } 

the problem happens on getview method:

@override public view getview(int position, view convertview, viewgroup parent) {      view view = convertview == null ?             activity.getlayoutinflater().inflate(r.layout.row_playlist, parent, false)             : convertview;      textview nometextview = (textview) view.findviewbyid(r.id.playlist_nome);     object item;      if(getitemviewtype(position) == type_playlist) {         item = (playlist) getitem(position);         nometextview.settext("- "+ item.getnome());     } else {         item = (musica) getitem(position);         nometextview.settext(item.getnome());     }      return view; } 

the "item", object type, doesn't recognize methods when casted type playlist or musica. try use method "getnome()" created in playlist class, doesn't work because item object. how can use child method?