How to pause the previous media file when clicking on a new one?

Question

Java

I have an android application in java,
when the button is pressed, the function of playing the file in the sound is substituted for the current MediaPlayer, in the same place clearing the memory after playing onCompletion. How to do if one media file is playing, when you click on another button, the second one is played, but the first one stops.

public void soundPlay(MediaPlayer sound) {
       
        sound.start();
        sound.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
            @Override
            public void onCompletion(MediaPlayer mp) {
                mp.release();;
            }
        });
       
    }

I tried to make it in this way, too, we give an error if you click on the same sound file twice

public void soundPlay(MediaPlayer sound) {
        if(m != null) {
            m.stop();
        }
        sound.start();
        sound.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
            @Override
            public void onCompletion(MediaPlayer mp) {
                mp.release();;
            }
        });
        m = sound;
    }