AudioSample on Android

AudioActivity.java

package org.example.sample.audio;

import android.app.Activity;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import java.io.IOException;

public class AudioActivity extends Activity {
    private static final String TAG = "AudioActivity";
    private MediaPlayer mp;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        Log.d(TAG, "onCreate");
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        setVolumeControlStream(AudioManager.STREAM_MUSIC);
    }

    @Override
    public final void onStart() {
        super.onStart();
        Log.d(TAG, "onStart");
        // Release the resource of a previus player.
        if (mp != null) mp.release();

        mp = MediaPlayer.create(this, R.raw.music);
        mp.setLooping(true);
        mp.start();
    }

    @Override
    public final void onPause() {
        Log.d(TAG, "onPause");
        super.onPause();
        if (mp != null && mp.isPlaying()) {
            mp.pause();
        }
    }

/*
  If you start the music on onResume(), music will start on Lock screen.
    @Override
    public final void onResume() {
        Log.d(TAG, "onResume");
        if (mp != null && mp.isPlaying() == false) {
            mp.start();
        }

        super.onResume();
    }
*/
    @Override
    public final void onStop() {
        Log.d(TAG, "onStop");
        /* When the activity is in background, music is stopped. */
        if (mp != null) {
            mp.stop();
            mp.release();
            mp = null;
        }
        super.onStop();
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        Log.d(TAG, "onWindowFocusChanged: " + hasFocus);
        if (hasFocus && mp != null && ! mp.isPlaying()) {
            mp.start();
        }
        super.onWindowFocusChanged(hasFocus);
    }
}