Android MediaPlayer 无法开始播放音频

Question

I have a very simple Android application where an audio file should start playing as soon as the app opens up.

But the audio doesn't play at all and I get this warning in Logcat: MediaPlayer finalized without being released

MainActivity.java:

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        MediaPlayer mPlayer = MediaPlayer.create(this, R.raw.song);

        mPlayer.start();
    }
}

I initialized MediaPlayer with the MediaPlayer.create() method, so I shouldn't have to prepare or release the mPlayer.

I'm not sure if it's a problem in my code or just a sound output problem with the android emulator.

UPDATE: I tried to declare the MediaPlayer outside of the onCreate() method and initialize it inside onCreate(). Now I don't get the warning but it still doesn't play the audio.

Updated MainActivity.java:

public class MainActivity extends AppCompatActivity {

    MediaPlayer mPlayer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mPlayer = MediaPlayer.create(this, R.raw.song);

        mPlayer.start();
    }
}

UPDATE 2: I added 3 callbacks, onPreparedListener, onErrorListener, and onCompletionListener in my application.

Updated MainActivity.java

public class MainActivity extends AppCompatActivity {

    MediaPlayer mPlayer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mPlayer = MediaPlayer.create(this, R.raw.song);

        mPlayer.setOnErrorListener(new MediaPlayer.OnErrorListener() {
            @Override
            public boolean onError(MediaPlayer mp, int what, int extra) {
                Log.e("Error", "onError: " + what);
                return false;
            }
        });

        mPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
            @Override
            public void onCompletion(MediaPlayer mp) {
                Log.i("Completion", "onCompletion: Completed");
            }
        });

        mPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
            @Override
            public void onPrepared(MediaPlayer mp) {
                Log.i("Prepared", "onPrepared: Prepared MediaPlayer");
            }
        });

        mPlayer.start();
    }
}

I get the prepared log pretty much as soon as the app starts, and I get the completed log after I wait out the duration of my audio file. I don't get any error logs in between.

Answer 1

The first you must declare the class of MediaPlayer,

MediaPlayer mediaPlayer = new MediaPlayer();
mediaPlayer.create(this, R.raw.song);
mediaPlayer.prepare();
mediaPlayer.start();

I expect this code work and helpful to everyone that read this post