Develop Reference

Android MediaPlayer : IllegalStateException when app closes/press back button

Im streaming an mp3 audio from a url by using mediaplayer, Now im able to play music , But when i press back button or close the app, it crashes.
can anyone pls help me to find my mistake.
thank you.
My code is :
private ImageView play, forward, backward;
private MediaPlayer mediaPlayer;
private boolean playing = false;
private ProgressDialog dialog;
private String mp3link;
private SeekBar seekbar;
private Handler handler = new Handler();
private int mediaPos;
private int mediaMax;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final String url ="";
initWidgets();
}
private void initWidgets() {
mp3link = "http://loc8app.com/church/uploads/audio/749928ad6fcb7b1aceefdf03bd7a9465.mp3";
play = (ImageView) findViewById(R.id.control);
seekbar = (SeekBar) findViewById(R.id.seekBar);
// forward = (ImageView) findViewById(R.id.playeer_forward);
// backward = (ImageView) findViewById(R.id.playeer_back);
mediaPlayer = new MediaPlayer();
play.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
playFunction();
}
});
seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
if(mediaPlayer != null && fromUser){
mediaPlayer.seekTo(progress);
}
}
});
}
private void playFunction() {
if (!playing) {
try {
dialog = ProgressDialog
.show(MainActivity.this,
"",
getString(com.root5solutions.music.R.string.buffering),
true);
dialog.setCancelable(true);
dialog.show();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDataSource(mp3link);
mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
#Override
public void onPrepared(MediaPlayer mp) {
play.setBackgroundResource(R.drawable.pause);
playing = true;
//this is new
mediaPos = mp.getCurrentPosition();
mediaMax = mp.getDuration();
seekbar.setMax(mediaMax);
seekbar.setProgress(mediaPos);
//this line is the error
handler.removeCallbacks(moveSeekBarThread);
handler.postDelayed(moveSeekBarThread, 100);
mp.start();
dialog.dismiss();
}
});
mediaPlayer.prepareAsync();
} catch (Exception e) {
e.printStackTrace();
dialog.dismiss();
}
} else {
play.setBackgroundResource(R.drawable.play);
mediaPlayer.stop();
mediaPlayer.release();
playing = false;
}
}
#Override
public void onBackPressed() {
super.onBackPressed();
if (mediaPlayer.isPlaying()) {
mediaPlayer.stop();
mediaPlayer.release();
}
}
private Runnable moveSeekBarThread = new Runnable() {
public void run() {
if (mediaPlayer.isPlaying()) {
int mediaPos_new = mediaPlayer.getCurrentPosition();
int mediaMax_new = mediaPlayer.getDuration();
seekbar.setMax(mediaMax_new);
seekbar.setProgress(mediaPos_new);
handler.postDelayed(this, 1000); // Looping the thread after 1 second
}
}
};
}
Logcat shows :
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.root.music, PID: 26981
java.lang.IllegalStateException
at android.media.MediaPlayer.isPlaying(Native Method)
at com.root.music.MainActivity$4.run(MainActivity.java:132)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5351)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:947)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:742)

The issue appears to be being caused by the moveSeekBarThread Runnable, from which the exception is being raised, continuing to execute after mediaPlayer is released in onBackPressed(). This results in the the isPlaying() method being executed, which as per the documentation will result in an IllegalStateException:
if the internal player engine has not been initialized or has been released.
Looking at moveSeekBarThread, it seems to be configured to reschedule itself endlessly by posting itself back into the handler Handler instance with a delay. This process is not being stopped when the user leaves the activity, which explains why moveSeekBarThread keeps running. So, based on the above, one solution could be to make sure that any instances of moveSeekBarThread in handler's queue are removed before calling mediaPlayer.release() when the user leaves the activity.
You should be able to do that by calling handler.removeCallbacks(moveSeekBarThread); before you call mediaPlayer.release(). For example, as follows:
#Override
public void onBackPressed() {
super.onBackPressed();
handler.removeCallbacks(moveSeekBarThread);
if (mediaPlayer.isPlaying()) {
mediaPlayer.stop();
mediaPlayer.release();
}
}
It should be okay to call it right before mediaPlayer.release(), but I think it's safer to call it regardless of whether mediaPlayer is playing. This way, if the Runnable does get or remain started somehow despite the media player not having being started or having been stopped, the Runnable will still be cleared.
As an aside, while I don't have any experience with MediaPlayer, I happened to notice that the documentation of the release method has the following to say:
It is considered good practice to call this method when you're done using the MediaPlayer. In particular, whenever an Activity of an application is paused (its onPause() method is called), or stopped (its onStop() method is called), this method should be invoked to release the MediaPlayer object, unless the application has a special need to keep the object around. In addition to unnecessary resources (such as memory and instances of codecs) being held, failure to call this method immediately if a MediaPlayer object is no longer needed may also lead to continuous battery consumption for mobile devices, and playback failure for other applications if no multiple instances of the same codec are supported on a device.
So unless there is that special need to keep the media player around in the activity in your case, it might be better to handle the release process (including clearing moveSeekBarThread from handler) in onPause or onStop instead.
Hope that helps!

you are getting IllegalStateException .
Signals that a method has been invoked at an illegal or inappropriate
time .
Call super.onBackPressed(); after if condition
#Override
public void onBackPressed()
{
if (mediaPlayer!= null)
{
if(mediaPlayer.isPlaying())
mediaPlayer.stop();
mediaPlayer.release();
}
super.onBackPressed(); // Call here
}

First you need to understand what illegalStateException means:
According to Android docs:
It Signals that a method has been invoked at an illegal or inappropriate time. In other words, the Java environment or Java application is not in an appropriate state for the requested operation.
have a look at the state diagram of a media player:
https://developer.android.com/images/mediaplayer_state_diagram.gif
Calling setDataSource(FileDescriptor), or setDataSource(String), or setDataSource(Context, Uri), or setDataSource(FileDescriptor, long, long), or setDataSource(MediaDataSource) transfers a MediaPlayer object in the Idle state to the Initialized state.
An IllegalStateException is thrown if setDataSource() is called in any other state.
It is good programming practice to always look out for IllegalArgumentException and IOException that may be thrown from the overloaded setDataSource methods.

Releasing Media Player while preparing is causing app to freeze

I have two activities a main activity which has Recyclerview and a detailedActivity which is launched every time the user clicks on one of the items of the Recyclerview. The detailedActivity has a mediaplayer component that is being created everytime a detailedActivity is created. Now in the onDestroy method I always free the resources taken by the mediaPlayer by this code:
#Override
protected void onDestroy() {
if (mMediaPlayer != null) {
if (mMediaPlayer.isPlaying()) {
mMediaPlayer.stop();}
mMediaPlayer.release();
mMediaPlayer=null;
}
super.onDestroy();
}
The app freezes for a while every time I click the back button while the mediaplayer is still preparing. The message that I get in the logcat is this:
I/Choreographer: Skipped 112 frames! The application may be doing too much work on its main thread.
So this freezing only happens if I destroyed the activity while it is preparing but if it is already in the prepared state it won't happen. I use prepreAsync to fetch the media from the internet.
Thanks. Any help is highly appreciated. I have been stuck in this problem for days!

OK. I've kind of worked around the problem. I am writing this for anyone who might encounter the same situation as I did. I made two boolean flags in the scope of the class like this:
boolean prepared = false;
boolean cancel = false;
After that in the onpreapred method I set prepared to true.
mMediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
#Override
public void onPrepared(MediaPlayer mp) {
prepared = true;
}
});
In the onDestroy method I check whether the mediaplayer is already prepared or not if prepared I release it from the method its self.
#Override
protected void onDestroy() {
if (mMediaPlayer != null) {
if (mMediaPlayer.isPlaying()) {
mMediaPlayer.stop();
}
if (prepared) {
mMediaPlayer.release();
mMediaPlayer = null;
}
cancel = true;
}
super.onDestroy();
}
Otherwise, I set cancel to true and implement on OnBufferingUpdateListener interface and override its method and release the mediaplayer from there.
#Override
public void onBufferingUpdate(MediaPlayer mp, int percent) {
if (cancel) {
mp.reset();
mp.release();
mMediaPlayer = null;
Log.i("msg", " mp released");
}
}

Try to remove rechecking if mediaplayer is running or not.
#Override
protected void onDestroy() {
if (mMediaPlayer != null) {
mMediaPlayer.stop();
mMediaPlayer.release();
}
super.onDestroy();
}
If it still happens, try to remove checking mediaplayer in your onDestroy().
-- UPDATE --
This could be related with this bug:
https://code.google.com/p/android/issues/detail?id=959
This could be a help:
Android MediaPlayer reset freezes UI

MediaPlayer to play music across Activites

I'd like to play music across Activities and I'm using a simple class to implement it. This class ( BackgroundMusic ) starts the music with MediaPlayer when I call the startMusic() method and stops it when I call the stopMusic() method. When I use it only in one Activity it works perfectly. OnCreate calls startMusic() method and onPause calls stopMusic() method and the MediaPlayer behave on the right way. The problem starts when I'd like to move to another Activity. When I'd like to stop the music it throws me NullPointerExepction for the mediaplayer.stop() . So it looks like the app thinks that I want to stop a never started MediaPlayer. I tried to call the startMusic() method in every onCreate method but the music starts again and again and I'd like to play only one music which don't stop and starts again when I move to another Activity. Is it possible to do that with class or I have to use Service? I hope you can help me to that with class.
BackgroundMusic
public void startMusic() {
mediaPlayer1 = MediaPlayer.create(context, R.raw.zenenegy);
if(palya <= 5 || palya > 15){
mediaPlayer1.start();
mediaPlayer1.setVolume(0.2f, 0.2f);
mediaPlayer1.setLooping(true);
play = true;
}
}
public void stopMusic(){
if(play){
mediaPlayer1.stop();
mediaPlayer1.reset();
mediaPlayer1.release();
mediaPlayer1 = null;
play = false;
}
}
An Activity
BackgroundMusic bm;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fomenu);
bm = new BackgroundMusic(mentes,this);
if(sounds){
bm.startMusic();
}
}
#Override
protected void onPause() {
if(sounds){
bm.stopMusic();
}
super.onPause();
}

If I set the mediaplayer to static in the BackgroundMusic it works perfectly.

How to release media player while preparing

I am working on music player app where I am doing streaming of music using MediaPlayer. Streaming is working fine but now I want If user press back button of the activity then it should stop preparing & release media player immediately.
Currently when it is preparing and if activity is being destroyed then I am releasing the MediaPlayer like this but when it release it then it hangs the application & show ANR.
#Override
protected void onDestroy() {
super.onDestroy();
if(mediaPlayer!=null) {
mediaPlayer.stop();
mediaPlayer.release();
}
}
I am initializing MediaPlayer like below
mediaPlayer = null;
mediaPlayer = new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDataSource("http://www.samisite.com/sound/cropShadesofGrayMonkees.mp3");
Now I want when it start preparing then on back press when I am releasing in onDestory then it should not hang the app & release the media player smoothly.
Please help me what is the best way to do this. Thanks in advance
mediaPlayer.prepareAsync();

Check the answer here. And the MediaPlayer State Diagram from android code.
Edit:
#TGMCians I showed him the provided link, So, if the playback is still not ready or preparing, he can not call stop() until it's called onPrepared. I'm not sure that onPrepared keep called after the app onDestroy called. So, The full snip I think is:
private boolean mPrepared = false;
private boolean mCancel = false;
public void onPrepared(MediaPlayer player){
mPrepared = true;
if(mCancel){
player.release();
mPrepared = false;
mCancel = false;
//nullify your MediaPlayer reference
mediaPlayer = null;
}
}
private void cancelMedia(){
mCancel = true;
}
#Override
protected void onDestroy() {
super.onDestroy();
cancelMedia();
if (mediaPlayer != null && mPrepared) {
mediaPlayer.stop();
mediaPlayer.release();
mPrepared = false;
mediaPlayer = null;
}
}

Is my code sufficient to prevent MediaPlayer leakage?

In my Activity I have the following:
private Set<MediaPlayer> mediaPlayers;
public void onSomeEventInMyActivity()
{
// play sound
MediaPlayer mediaPlayer = MediaPlayer.create(this, R.raw.my_sound);
mediaPlayers.add(mediaPlayer);
mediaPlayer.setOnCompletionListener(new OnCompletionListener()
{
#Override
public void onCompletion(MediaPlayer mp)
{
mp.release();
mediaPlayers.remove(mp);
}
});
mediaPlayer.start();
}
#Override
protected void onStart()
{
super.onStart();
mediaPlayers = new HashSet<MediaPlayer>();
}
#Override
protected void onStop()
{
super.onStop();
for (MediaPlayer mediaPlayer : mediaPlayers)
{
if (mediaPlayer.isPlaying())
{
mediaPlayer.stop();
}
mediaPlayer.release();
}
}
Is this code sufficient or will it lead to MediaPlayer leakage? Are my implementations of onStop and onStart necessary, or can I just rely on calling release in onCompletion?
I did my code this way because I assume onStop() could be called while a MediaPlayer is playing, so I need to call release because onCompletion won't be called yet. I'm just guessing that this is right, so correct me if I am wrong.
I also read that onStop is not called in low-memory situations - what to do then?

An onStop() routine is needed if the mediaPlayer is expected to stop when the activity becomes invisible. Otherwise, the mediaPlayer goes on playing. On older OSs, Gingerbread and earlier, the activity can execute onPause() - say, when a phone call arrives - and, in extreme circumstances, be destroyed without ever executing onStop(). I don't know what would happen to a running mediaPlayer then. However, if there is a phone call coming in, it might be an idea to stop the mediaPlayer in onPause()! Later OSs always pass through onStop() before destroying the Activity. Calling mp.release() on the mediaPlayer after stopping it, in either onPause() or onStop(), is correct.
It's also desirable to remove the reference to the player held in mediaPlayers, which doesn't happen in onStop() above. Something like:
#Override public void onCompletion(MediaPlayer mp) {
mp.stop(); // It's always safe to call stop()
mp.release(); // release resources internal to the MediaPlayer
mediaPlayers.remove(mp); // remove reference to MediaPlayer to allow GC
}
and then
#Override public void onPause() {
for (Object mediaPlayer : mediaPlayers.toArray()) {
onCompletion((MediaPlayer) mediaPlayer); // stop, release, and free for GC, each mp.
}
super.onPause();
}
(I originally had for (Object mediaPlayer : mediaPlayers) {} in the above code but omfeddf345mnof32nisd45fgoq2t pointed out that I would be modifying a set while iterating over it. Thanks for the correction!)

Only callback guaranted to be called is onPause(), so you may leak this media player in some situations. In case stopping player on activity pause is not acceptable you should use service, and watch for certain events ( like incoming phone call etc )