呈现genericlistrenderer时出现空指针异常

Question

super.beforeMain(f);
   final List list = findList(f);
   Component selected = createContainer(fetchResourceFile(), "Renderer");
   Component unselected = createContainer(fetchResourceFile(), "Renderer");
   System.out.println(selected.getName());
   list.setRenderer(new GenericListCellRenderer(selected, unselected) {
      public Component getListCellRendererComponent(List list, Object value, int index, boolean isSelected) {
         if ((index + 1) >= list.size()) {
            fetchMore(list);
         }
         return super.getListCellRendererComponent(list, value, index, isSelected);
      }

        private void fetchMore(final List list) {
            // TODO Auto-generated method stub


            // TODO Auto-generated method stub
            NetworkManager networkManager = NetworkManager.getInstance();
            networkManager.start();
            networkManager.addErrorListener(new ActionListener() {
             public void actionPerformed(ActionEvent evt) {
             NetworkEvent n = (NetworkEvent) evt;
                n.getError().printStackTrace();                        
             }});   

            ConnectionRequest request = new ConnectionRequest() {

                String array[] ;
                String images[];
                //StringBuffer sb = new StringBuffer();  
                Hashtable h;
                Vector tweets;
               // @Override
                protected void postResponse() {

                    //cmp.setModel(new com.codename1.ui.list.DefaultListModel(array));


                }
                protected void readResponse(InputStream input) throws IOException {


                    Result result = Result.fromContent(input, Result.XML);


                     array = result.getAsStringArray("/music[1]//thumb_url");

                     int count = list.size();

                     for (int i = 0; i < array.length; i++) {
                           // Hashtable tweet = (Hashtable)tweets.elementAt(i);
                            list.addItem(array[i]);
                            addAvatar(list, array[i], count + i);
                         }
                    System.out.println(""+array.length);


                }  
                private void addAvatar(List list, String array, int i) {
                    // TODO Auto-generated method stub


                    //String url = (String)array.get("profile_image_url");
                    //String user = (String)array.get("from_user");
                   // if (array == null || array.startsWith("http:") == false) {
                       // ImageDownloadService doesn't support HTTPS at moment
                     //  return;
                    //}
                    ImageDownloadService ids = new ImageDownloadService(array, list, i, "avatar");
                    ids.setDuplicateSupported(true);
                    NetworkManager.getInstance().addToQueue(ids);
                    ImageDownloadService.createImageToStorage(array, list, i, "avatar", "-avatar",
                         new Dimension(48, 48));



                }

                protected void handleException(Exception err) {
                     //An error occured - show a message:
           Dialog.show("Alert", "Are you connected to the internet? Check your connection", "Ok", null);
               }
            };
            request.setUrl("http://api.androidhive.info/music/music.xml");    //servlet calling
            request.setPost(false);
            //infiniteProgress prog=
            InfiniteProgress prog=new InfiniteProgress();
            Dialog dlg=prog.showInifiniteBlocking();
            request.setDisposeOnCompletion(dlg);
            networkManager.addToQueueAndWait(request);
                        }


   });    }

以下是在sun.reflect.nativeMethodAccessorImpl.Invoke0（本机方法）在sun.reflect.nativeMethodAccessorImpl.Invoke（未知源）在sun.reflect.NativeMethodAccessorImpl.Invoke（未知源）在java.lang.Reflect.Method.Invoke（未知源）在com.codename1.impl.javase.Executor$1.run在com.codename1.impl.codenameOnethread.run(runnableWrapper.java:120)由:java.lang.nullPointerException在userclasses.statemachine.beforeMain(statemachine.java:117)在generated.statemachineBase.beforeShow(statemachineBase.java:218)在com.codename1.ui.util.uiBuilder.showform(UiBuilder.java:2436)在StateMachineBase.StartApp（StateMachinebase.java:57)在generated.stateMachineBase.(stateMachineBase.java:31)在generated.stateMachineBase.(stateMachineBase.java:100)在userclasses.stateMachine.(stateMachine.java:38)在com.prime.cnna.myapplication.start(myapplication.java:62)
在list.setrenderer（new GenericListCellRenderer（selected,unselected）{}以下行出现空指针