Akshay Sharma Akshay Sharma - 1 year ago 90
Android Question

Invalid Index is Zero on Playing Song

I am creating a music player app. I have two classes named "Tab3Tracks" and "NowPlaying". In "Tab3Tacks" class, songs are loaded in ListView. So that when someone clicks on a song, it sends position of that song to other class so that other class will able to play that song. But i am getting error while clicking on song. I dont know where i am making mistake. In logcat, i received error "Invalid Index 0, size is 0" in NowPlaying class. I am posting LogCat error code. Check my code for any mistakes. Thanks in advance.

Tab3Tracks Class

public class Tab3Tracks extends ListFragment {

public void onCreate(Bundle savedInstanceState){

private ArrayList<String> trackslist = new ArrayList<>();

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.tab3tracks, container, false);

final String trackid = MediaStore.Audio.Media._ID;
final String trackno = MediaStore.Audio.Media.TRACK;
final String trackname = MediaStore.Audio.Media.TITLE;
final String path = MediaStore.Audio.Media.DATA;
Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;

ContentResolver cr = getContext().getContentResolver();
final String[] projection = {trackid,trackno,trackname,path
final Cursor cursor = cr.query(uri,projection,null,null,null);
if (cursor!=null){
int trackIndex = cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.TITLE);
} cursor.close();
ArrayAdapter<String> adapter = new ArrayAdapter<String>(
return v;

public ArrayList<String> getList(){
return trackslist;

public void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
int songIndex = position;

// Starting new intent
Intent in = new Intent(getActivity(), NowPlaying.class);
// Sending songIndex to PlayerActivity
in.putExtra("songIndex", songIndex);
startActivityForResult(in, 100);

NowPlaying Class

public class NowPlaying extends AppCompatActivity {

public ArrayList<String> songsList = new ArrayList<String>();
public Tab3Tracks tab3tracks;

protected void onCreate(Bundle savedInstanceState) {
// Getting all songs list
tab3tracks = new Tab3Tracks();
songsList= tab3tracks.getList();

// By default play first song


* Receiving song index from playlist view
* and play the song
protected void onActivityResult(int requestCode,
int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == 100) {
currentSongIndex = data.getExtras().getInt("songIndex");
// play selected song


* Function to play a song
* @param songIndex - index of song
public void playSong(int songIndex) {
// Play song
try {
// Displaying Song title
String songTitle = songsList.get(songIndex);

// Changing Button Image to pause image

// set Progress bar values

// Updating progress bar
} catch (IllegalArgumentException e) {
} catch (IllegalStateException e) {
} catch (IOException e) {

LogCat Error

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.digital.thefearstuff.tfsmusicplayer/com.digital.thefearstuff.tfsmusicplayer.NowPlaying}: java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2450)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2520)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1363)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5466)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
at java.util.ArrayList.get(ArrayList.java:308)
at com.digital.thefearstuff.tfsmusicplayer.NowPlaying.playSong(NowPlaying.java:286)
at com.digital.thefearstuff.tfsmusicplayer.NowPlaying.onCreate(NowPlaying.java:83)
at android.app.Activity.performCreate(Activity.java:6251)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1108)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2403)

Answer Source

Firstly, please avoid asking such questions as Why is this code not working? seeking debug help, since they tend to get a lot of downvotes and are usually quickly closed off. Always try to minimize and isolate your problem. Debug by yourself and see How to create a Minimal, Complete, and Verifiable example for future posts.

Now to question, here in playSong(0) you try to access element at position 0 but the list is empty and there is no such position, therefore IndexOutOfBounds.

    at com.digital.thefearstuff.tfsmusicplayer.NowPlaying.playSong(NowPlaying.java:286)
    at com.digital.thefearstuff.tfsmusicplayer.NowPlaying.onCreate(NowPlaying.java:83)

Your songsList is as it turns out - empty. Which in turn means that trackslist is empty. Which for itself could lead to cursor being null and skipping the add-while-loop. But that you should debug by yourself since you only have the whole code.

To debug it: Add an else and Log with the if (cursor != null){ such as

if (cursor!=null){
            int trackIndex = cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.TITLE);
} else {
    Log.d("cursor", "null");

and look for it in the logcat.

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