Android Mediaplayer play different songs after eachother

Question

I generate midi files on the go. I want to play these files continuously.

I initialise a mediaplayer and start song1.mid. Then I use the following code to play song2.mid

// set on completion listener music file
                mediaPlayer
                        .setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                            @Override
                            public void onCompletion(MediaPlayer mp) {

                                String filePath2 = null;
                                File file = null;
                                FileInputStream inputStream = null;

                                //set the filePath
                                try {
                                    filePath2 = getCacheDir() + "/optimuse" + song + ".mid";
                                    file = new File(filePath2);
                                    if (file.exists()) {
                                        inputStream = new FileInputStream(file);
                                        if (inputStream.getFD().valid()) {
                                            System.out.println("Valid!");
                                        }
                                    }
                                } catch (Exception e1) {
                                    e1.printStackTrace();
                                    System.exit(-1);
                                }

                                //set Mediaplayer's datasource
                                if (file.exists()) {
                                    try {
                                        mediaPlayer = new MediaPlayer();
                                        mediaPlayer.setDataSource(inputStream.getFD());
                                        inputStream.close();
                                    } catch (Exception e1) {
                                        e1.printStackTrace();
                                        System.exit(-1);
                                    }

                                    try {
                                        mediaPlayer.prepare();
                                    } catch (IllegalStateException e) {

                                        e.printStackTrace();
                                    } catch (IOException e) {
                                        e.printStackTrace();
                                    }
                                }

                                //if the player is not running
                                if (!mediaPlayer.isPlaying()) {
                                    //start the player
                                    mediaPlayer.start();
                                    Toast.makeText(MainActivity.this,
                                            "mediaPlayer.start()", Toast.LENGTH_LONG)
                                            .show();
                                }
                            }
                        });                         


                            }
                        });

The problem is that the mediaplayer stops after song2. But I want song3 to start. I can increment the global variable, ok. But the onCompletionListener does not seem to work when the second song finishes.

I guess I should initialise MediaPlayer mp to have an onCompletionListener too? Not sure what the best approach is.

Or should I do something like:

new class MediaPlayer implements OnCompletionListener(){
@Override
song++;
//code to start the mediaplayer
}

Thank you for putting me in the right direction. I am also a little bit concerned with efficiency, when I keep starting up new mediaplayers...

Basically, what I want to do is play song1.mid, song2.mid,... continuously, but the files are generated during the program.

EDIT Thanks to the wonderful help of @Gan. I know have the following working code:

            // set on completion listener music file
            mediaPlayer
                    .setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                        @Override
                        public void onCompletion(MediaPlayer mp) {

                            String filePath2 = null;
                            File file = null;
                            FileInputStream inputStream = null;

                            //set the filePath
                            try {
                                filePath2 = getCacheDir() + "/optimuse" + song + ".mid";
                                file = new File(filePath2);
                                if (file.exists()) {
                                    inputStream = new FileInputStream(file);
                                    if (inputStream.getFD().valid()) {
                                        System.out.println("Valid!");
                                    }
                                }
                            } catch (Exception e1) {
                                e1.printStackTrace();
                                System.exit(-1);
                            }

                            //set Mediaplayer's datasource
                            if (file.exists()) {
                                try {

                                    mp.stop();
                                    mp.reset();
                                    mp.setDataSource(inputStream.getFD());
                                    inputStream.close();
                                } catch (Exception e1) {
                                    e1.printStackTrace();
                                    System.exit(-1);
                                }

                                try {
                                    mp.prepare();
                                } catch (IllegalStateException e) {

                                    e.printStackTrace();
                                } catch (IOException e) {
                                    e.printStackTrace();
                                }
                            }

                            //if the player is not running
                            if (!mp.isPlaying()) {
                                //start the player
                                mp.start();
                                Toast.makeText(MainActivity.this,
                                        "mp.start()", Toast.LENGTH_LONG)
                                        .show();
                            }


                        }
                    });                         


                        }
                    });

Solution

store the source locations in an array and in the onCompletionListener cycle through the source. something like this (use the same media player instance)

mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mp) 
{
   if(currentPosition<sourceArray.size())
   {
        mediaPlayer.reset();
       /* load the new source */
       mediaPlayer.setDataSource(sourceArray[position]);
       /* Prepare the mediaplayer */
       mediaPlayer.prepare();
       /* start */
       mediaPlayer.start();
   }
   else
   {
       /* release mediaplayer */
       mediaPlayer.release();
   }
 }

Comments

[dorien]

Thanks, but mediaPlayer doesn't seem to go to oncompletionlistener after the second song ends (at least it does not do it now). Because with the current code, it should keep repeating song2.mid, but it does not (I which it did, lol)

[Gan]

i see that in your code that you have created a new instance and you did not set the onCompletionListener. if you use a new instance you have to specify the onCompletionListener every time.

[Gan]

Try using the same instance, its more efficient.

[dorien]

That seems to make sence, but How do I do that? If I delete @Override public void onCompletion(MediaPlayer mp) { }); it doesn't want to compile.

[Gan]

you have to override the onCompletion method since its the callback method. just follow the edited code. just load the next source file in the mediaplayer, prepare it and start it. ( I assume that you have stored the source file locations in the soureceArray and position is a just counter to cycle through the array)

[dorien]

Thanks! Ok, I see I shouldn't call mediaPlayer = new MediaPlayer(); I deleted this and now I still get a runtime error attachNewPlayer called. Let me debug...

[dorien]

Got it! Wow great! So stupid, I had to use mp instead of mediaPlayer (of course). And add a mp.stop() and mp.reset(). I have put my working code as an edit in my question, I hope that is ok.

[Gan]

@dorien, stop is not necessary, but reset is! ( i somehow forgot that, i have edited it now). you can also use mediaPlayer, but using mp is better.