Question
I'd like to implement EndlessAdapter from commonsware in my application, it is a Listfragment with a Custom ListView and a lazyadapter that extends Baseadapter.
Problem:
I´m getting an Exception in cacheInBackground(); when I call MyAsyncTask, any help to solve? I´ve used the Endlessadapter v1.2 (latest) as library.
https://stackoverflow.com/questions/14091554
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Russian @Override
protected boolean cacheInBackground() {
new MyAsyncTask(this, data.size()).execute();
return hasMoreData;
}
The Lazyadapter is working well without EndlessAdapter.
12-30 15:29:21.404: E/EndlessAdapter(334): Exception in cacheInBackground() 12-30 15:29:21.404: E/EndlessAdapter(334): java.lang.NullPointerException 12-30 15:29:21.404: E/EndlessAdapter(334): at br.com.example.nightid.endlessadapter.EndlessCustomView$DemoAdapter.cacheInBackground(EndlessCustomView.java:132) 12-30 15:29:21.404: E/EndlessAdapter(334): at com.commonsware.cwac.endless.EndlessAdapter.getView(EndlessAdapter.java:250) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.AbsListView.obtainView(AbsListView.java:1430) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.ListView.makeAndAddView(ListView.java:1745) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.ListView.fillDown(ListView.java:670) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.ListView.fillFromTop(ListView.java:727) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.ListView.layoutChildren(ListView.java:1598) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.AbsListView.onLayout(AbsListView.java:1260) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.view.View.layout(View.java:7175) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.FrameLayout.onLayout(FrameLayout.java:338) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.view.View.layout(View.java:7175) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.FrameLayout.onLayout(FrameLayout.java:338) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.view.View.layout(View.java:7175) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.FrameLayout.onLayout(FrameLayout.java:338) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.view.View.layout(View.java:7175) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.support.v4.view.ViewPager.onLayout(ViewPager.java:1520) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.view.View.layout(View.java:7175) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1254) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1130) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.LinearLayout.onLayout(LinearLayout.java:1047) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.view.View.layout(View.java:7175) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.FrameLayout.onLayout(FrameLayout.java:338) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.view.View.layout(View.java:7175) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1254) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1130) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.LinearLayout.onLayout(LinearLayout.java:1047) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.view.View.layout(View.java:7175) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.FrameLayout.onLayout(FrameLayout.java:338) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.view.View.layout(View.java:7175) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.widget.FrameLayout.onLayout(FrameLayout.java:338) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.view.View.layout(View.java:7175) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.view.ViewRoot.performTraversals(ViewRoot.java:1140) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.view.ViewRoot.handleMessage(ViewRoot.java:1859) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.os.Handler.dispatchMessage(Handler.java:99) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.os.Looper.loop(Looper.java:123) 12-30 15:29:21.404: E/EndlessAdapter(334): at android.app.ActivityThread.main(ActivityThread.java:3683) 12-30 15:29:21.404: E/EndlessAdapter(334): at java.lang.reflect.Method.invokeNative(Native Method) 12-30 15:29:21.404: E/EndlessAdapter(334): at java.lang.reflect.Method.invoke(Method.java:507) 12-30 15:29:21.404: E/EndlessAdapter(334): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 12-30 15:29:21.404: E/EndlessAdapter(334): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 12-30 15:29:21.404: E/EndlessAdapter(334): at dalvik.system.NativeStart.main(Native Method) 12-30 15:30:53.096: E/dalvikvm(334): Could not find class 'com.actionbarsherlock.widget.SearchView$11', referenced from method com.actionbarsherlock.widget.SearchView.
EndlessCustomView:
public class EndlessCustomView extends ListFragment{
// All static variables
static final String URL = "http://api.androidhive.info/music/music.xml";
// XML node keys
static final String KEY_SONG = "song"; // parent node
static final String KEY_ID = "id";
static final String KEY_TITLE = "title";
static final String KEY_ARTIST = "artist";
static final String KEY_DURATION = "duration";
static final String KEY_THUMB_URL = "thumb_url";
ListView list;
DemoAdapter adapter=null;
ArrayList<HashMap<String, String>> songsList = null;
// @Override
// public void onActivityCreated(Bundle savedInstanceState) {
// // TODO Auto-generated method stub
// super.onActivityCreated(savedInstanceState);
//
// setRetainInstance(true);
//
// songsList = new ArrayList<HashMap<String, String>>();
//
// if (getActivity() != null) {
//
// adapter = new DemoAdapter(getActivity(), songsList);
// adapter.setRunInBackground(false);
// setListAdapter(adapter);
// }
//
// }
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onViewCreated(view, savedInstanceState);
//
//// new MyAsyncTask().execute();
setRetainInstance(true);
songsList = new ArrayList<HashMap<String, String>>();
if (getActivity() != null) {
adapter = new DemoAdapter(getActivity(), songsList);
adapter.setRunInBackground(false);
setListAdapter(adapter);
}
}
class DemoAdapter extends EndlessAdapter implements IItemsReadyListener{
private RotateAnimation rotate=null;
private View pendingView=null;
private FragmentActivity activity;
private ArrayList<HashMap<String, String>> data;
public ImageLoader imageLoader;
private List<HashMap<String, String>> mOriginalNames;
private boolean hasMoreData=true;
DemoAdapter(FragmentActivity fragmentActivity, ArrayList<HashMap<String, String>> d) {
super(new LazyAdapter(fragmentActivity, d));
rotate=new RotateAnimation(0f, 360f, Animation.RELATIVE_TO_SELF,
0.5f, Animation.RELATIVE_TO_SELF,
0.5f);
rotate.setRepeatMode(Animation.RESTART);
rotate.setRepeatCount(Animation.INFINITE);
}
@Override
protected View getPendingView(ViewGroup parent) {
View row = getActivity().getLayoutInflater().inflate(R.layout.row, null);
View child=row.findViewById(android.R.id.text1);
child.setVisibility(View.GONE);
child=row.findViewById(R.id.throbber);
child.setVisibility(View.VISIBLE);
child.startAnimation(rotate);
return(row);
}
@Override
protected boolean cacheInBackground() {
new MyAsyncTask(this, data.size()).execute();
return hasMoreData;
}
public void onItemsReady(ArrayList<HashMap<String, String>> data) {
songsList.addAll(data);
adapter.onDataReady(); // Tell the EndlessAdapter to remove it's pending
// view and call notifyDataSetChanged()
hasMoreData = songsList.isEmpty();
}
@Override
protected void appendCachedData() {
// if (getWrappedAdapter().getCount()<75) {
// @SuppressWarnings("unchecked")
// LazyAdapter a=(LazyAdapter)getWrappedAdapter();
// for (int i = 0; i < data.size(); i++) {
// a.add(data.get(i));
// }
// }
}
public class MyAsyncTask extends AsyncTask<Void,Void,ArrayList<HashMap<String, String>>>{
IItemsReadyListener listener;
private final ProgressDialog dialog=new ProgressDialog(getActivity());
int startPoint;
public MyAsyncTask(IItemsReadyListener listener, int startPoint) {
// TODO Auto-generated constructor stub
this.listener = listener;
this.startPoint = startPoint;
}
@Override
protected ArrayList<HashMap<String, String>> doInBackground(Void... params) {
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl(URL); // getting XML from URL
Document doc = parser.getDomElement(xml); // getting DOM element
NodeList nl = doc.getElementsByTagName(KEY_SONG);
// looping through all song nodes <song>
for (int i = 0; i < nl.getLength(); i++) {
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element) nl.item(i);
// adding each child node to HashMap key => value
map.put(KEY_ID, parser.getValue(e, KEY_ID));
map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE));
map.put(KEY_ARTIST, parser.getValue(e, KEY_ARTIST));
map.put(KEY_DURATION, parser.getValue(e, KEY_DURATION));
map.put(KEY_THUMB_URL, parser.getValue(e, KEY_THUMB_URL));
// adding HashList to ArrayList
songsList.add(map);
}
return (songsList);
}
@Override
protected void onPreExecute()
{
dialog.setMessage("Loading ...");
dialog.show();
dialog.setCancelable(false);
}
@Override
protected void onPostExecute(ArrayList<HashMap<String, String>> result)
{
listener.onItemsReady(songsList);
// Getting adapter by passing xml data ArrayList
}
}
}
}
LazyAdapter:
public class LazyAdapter extends BaseAdapter {
private FragmentActivity activity;
private ArrayList<HashMap<String, String>> data;
private static LayoutInflater inflater=null;
public ImageLoader imageLoader;
private List<HashMap<String, String>> mOriginalNames;
public LazyAdapter(FragmentActivity fragmentActivity, ArrayList<HashMap<String, String>> d) {
super();
this.activity = fragmentActivity;
this.data = d;
inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
imageLoader=new ImageLoader(activity.getApplicationContext());
}
public int getCount() {
return data.size();
}
public Object getItem(int position) {
return data.get(position);
}
public long getItemId(int position) {
return position;
}
@Override
public void notifyDataSetChanged() {
super.notifyDataSetChanged();
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View vi=convertView;
if(convertView==null)
vi = inflater.inflate(R.layout.list_row, null);
TextView title = (TextView)vi.findViewById(R.id.title); // title
TextView artist = (TextView)vi.findViewById(R.id.artist); // artist name
TextView duration = (TextView)vi.findViewById(R.id.duration); // duration
ImageView thumb_image=(ImageView)vi.findViewById(R.id.list_image); // thumb image
HashMap<String, String> song = new HashMap<String, String>();
song = data.get(position);
// Setting all values in listview
title.setText(song.get(CustomizedListView.KEY_TITLE));
artist.setText(song.get(CustomizedListView.KEY_ARTIST));
duration.setText(song.get(CustomizedListView.KEY_DURATION));
imageLoader.DisplayImage(song.get(CustomizedListView.KEY_THUMB_URL), thumb_image);
return vi;
}
public void add(HashMap<String, String> map) {
// TODO Auto-generated method stub
data.add(map);
notifyDataSetChanged();
}
}
Solution
data is null in cacheInBackground(). You can tell this by reading your stack trace (NullPointerException in cacheInBackground()) and seeing that the only thing that could possibly trigger that exception right in cacheInBackground() is data.size().
Since I fail to see where you ever assign a value to data, the fact that is null is not that surprising.
