Check out example codes for "play mp3 android java". It will help you in understanding the concepts better.

Code Example 1

MediaPlayer mediaPlayer;
//In the onCreate Method
mediaPlayer = MediaPlayer.create(this, R.raw.alarmclockbuzzer);
//Sound file goes in "raw" folder in "res" folder
mediaPlayer.start(); //plays the mp3 sound (doesn't need to be in oncreate)

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