I am facing some problem while downloading images from the server and showing in the ListView using AsyncTask in Android.
It showing me error that downloading the images are in the Main (UI) Thread But I am using the AsyncTask for that purpose.
Here is my MainActivity.java code.
public class MainActivity extends AppCompatActivity {
private String[] imageURLArray = new String[]{
"http://farm8.staticflickr.com/7315/9046944633_881f24c4fa_s.jpg",
"http://farm4.staticflickr.com/3777/9049174610_bf51be8a07_s.jpg",
"http://farm8.staticflickr.com/7324/9046946887_d96a28376c_s.jpg",
"http://farm3.staticflickr.com/2828/9046946983_923887b17d_s.jpg",
"http://farm4.staticflickr.com/3810/9046947167_3a51fffa0b_s.jpg",
"http://farm4.staticflickr.com/3773/9049175264_b0ea30fa75_s.jpg",
"http://farm4.staticflickr.com/3781/9046945893_f27db35c7e_s.jpg",
"http://farm6.staticflickr.com/5344/9049177018_4621cb63db_s.jpg",
"http://farm8.staticflickr.com/7307/9046947621_67e0394f7b_s.jpg",
"http://farm6.staticflickr.com/5457/9046948185_3be564ac10_s.jpg",
"http://farm4.staticflickr.com/3752/9046946459_a41fbfe614_s.jpg",
"http://farm8.staticflickr.com/7403/9046946715_85f13b91e5_s.jpg",
"http://farm8.staticflickr.com/7315/9046944633_881f24c4fa_s.jpg",
"http://farm4.staticflickr.com/3777/9049174610_bf51be8a07_s.jpg",
"http://farm8.staticflickr.com/7324/9046946887_d96a28376c_s.jpg",
"http://farm3.staticflickr.com/2828/9046946983_923887b17d_s.jpg",
"http://farm4.staticflickr.com/3810/9046947167_3a51fffa0b_s.jpg",
"http://farm4.staticflickr.com/3773/9049175264_b0ea30fa75_s.jpg",
"http://farm4.staticflickr.com/3781/9046945893_f27db35c7e_s.jpg",
"http://farm6.staticflickr.com/5344/9049177018_4621cb63db_s.jpg",
"http://farm8.staticflickr.com/7307/9046947621_67e0394f7b_s.jpg",
"http://farm6.staticflickr.com/5457/9046948185_3be564ac10_s.jpg",
"http://farm4.staticflickr.com/3752/9046946459_a41fbfe614_s.jpg",
"http://farm8.staticflickr.com/7403/9046946715_85f13b91e5_s.jpg"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = (ListView)this.findViewById(R.id.listView);
ImageAdapter imageAdapter = new ImageAdapter(this, R.layout.imageitem, imageURLArray);
listView.setAdapter(imageAdapter);
}
}
Here is my ImageAdapter.java code.
public class ImageAdapter extends ArrayAdapter<String> {
private String[] imageURLArray;
private LayoutInflater inflater;
public ImageAdapter(Context context, int textViewResourceId,
String[] imageArray) {
super(context, textViewResourceId, imageArray);
// TODO Auto-generated constructor stub
inflater = ((Activity) context).getLayoutInflater();
imageURLArray = imageArray;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
ViewHolder viewHolder = null;
if (convertView == null) {
convertView = inflater.inflate(R.layout.imageitem, null);
viewHolder = new ViewHolder();
viewHolder.imageView = (ImageView) convertView.findViewById(R.id.testImage);
convertView.setTag(viewHolder);
}
viewHolder = (ViewHolder) convertView.getTag();
Bitmap imageBitmap = null;
try {
URL imageURL = new URL(imageURLArray[position]);
imageBitmap = BitmapFactory.decodeStream(imageURL.openStream());
viewHolder.imageView.setImageBitmap(imageBitmap);
} catch (IOException e) {
// TODO: handle exception
Log.e("error", "Downloading Image Failed");
viewHolder.imageView.setImageResource(R.mipmap.ic_launcher);
}
return convertView;
}
private static class ViewHolder {
Bitmap bitmap;
String imageURL;
ImageView imageView;
}
private class DownloadAsyncTask extends AsyncTask<ViewHolder, Void, ViewHolder> {
@Override
protected ViewHolder doInBackground(ViewHolder... params) {
// TODO Auto-generated method stub
//load image directly
ViewHolder viewHolder = params[0];
try {
URL imageURL = new URL(viewHolder.imageURL);
viewHolder.bitmap = BitmapFactory.decodeStream(imageURL.openStream());
} catch (IOException e) {
// TODO: handle exception
Log.e("error", "Downloading Image Failed");
viewHolder.bitmap = null;
}
return viewHolder;
}
@Override
protected void onPostExecute(ViewHolder result) {
if (result.bitmap == null) {
result.imageView.setImageResource(R.mipmap.ic_launcher);
} else {
result.imageView.setImageBitmap(result.bitmap);
}
}
}
}
Here is the link that have the full project.
http://www.mediafire.com/download/70pxv6ib584x9j7/DownloadImagesInListView.rar
Here is the error stack that is showing.
09-29 18:33:37.859 5550-5550/com.example.android.downloadimagesinlistview E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.android.downloadimagesinlistview, PID: 5550
android.os.NetworkOnMainThreadException
at
android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1161)
at java.net.InetAddress.lookupHostByName(InetAddress.java:418)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
at java.net.InetAddress.getAllByName(InetAddress.java:215)
at com.android.okhttp.HostResolver$1.getAllByName(HostResolver.java:29)
at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:232)
at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:124)
at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:272)
at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:211)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:382)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:332)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:199)
at java.net.URL.openStream(URL.java:470)
at com.example.android.downloadimagesinlistview.ImageAdapter.getView(ImageAdapter.java:48)
at android.widget.AbsListView.obtainView(AbsListView.java:2347)
at android.widget.ListView.makeAndAddView(ListView.java:1864)
at android.widget.ListView.fillDown(ListView.java:698)
at android.widget.ListView.fillFromTop(ListView.java:759)
at android.widget.ListView.layoutChildren(ListView.java:1673)
at android.widget.AbsListView.onLayout(AbsListView.java:2151)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.support.v7.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:437)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2116)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1873)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1084)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5990)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
at android.view.Choreographer.doCallbacks(Choreographer.java:580)
at android.view.Choreographer.doFrame(Choreographer.java:550)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5343)
at java.lang.reflect.Method.invoke(
This exception occurs when you perform network related operations on the main thread. For downloading the images either you have to perform the operation in AsyncTask or Use picasso library.
Using Picasso use this
Picasso.with(MainActivity.this).load(imageURLArray[position]).error(R.mipmap.ic_launcher).into(viewHolder.imageView);
at the place of
Bitmap imageBitmap = null;
try {
URL imageURL = new URL(imageURLArray[position]);
imageBitmap = BitmapFactory.decodeStream(imageURL.openStream());
viewHolder.imageView.setImageBitmap(imageBitmap);
} catch (IOException e) {
// TODO: handle exception
Log.e("error", "Downloading Image Failed");
viewHolder.imageView.setImageResource(R.mipmap.ic_launcher);
}