Mediaplayer Background Audio not work properly Using URL And Song Not Play Second Time

Question

This is my second activity and when open this activity threw button activity take load and open after some time and some times UI Freeze and some time black screen open for some seconds

public class AartiActivity extends AppCompatActivity {

    final MediaPlayer player1 = new MediaPlayer();
    private Button btn_playarti, btn_pausearti, btn_stoparti;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_aarti);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

        btn_playarti = (Button) findViewById(R.id.btn_playarti);
        btn_pausearti = (Button) findViewById(R.id.btn_pausearti);
        btn_stoparti = (Button) findViewById(R.id.btn_stoparti);

        try {
            player1.setDataSource(STRING_URL);
            player1.prepare();
        } catch (IOException e) {
            e.printStackTrace();
        }

        btn_playarti.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                player1.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                    @Override
                    public void onCompletion(MediaPlayer player) {
                        player.stop();
                    }
                });
                player1.start();
            }
        });

        btn_pausearti.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (player1.isPlaying()) {
                    player1.pause();
                }
            }
        });

        btn_stoparti.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                player1.stop();
            }
        });
    }

    @Override
    protected void onStop() {
        super.onStop();
        player1.stop();
    }
}