AudioPlayer app

MainActivity.java

package com.aasemjs.audioplayer;

import android.media.MediaPlayer;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    MediaPlayer mp;

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

        mp=MediaPlayer.create(this, R.raw.abc);
    }

    public void playSong(View v){
        mp.start();
    }

    public void pauseSong(View v) {
        mp.pause();
    }

    public void stopSong(View v) {
        mp.stop();
        mp=MediaPlayer.create(this, R.raw.abcd);
    }
}

it didn't work for me null pointer

Check Mine Out.
public class MainActivity extends AppCompatActivity {

MediaPlayer mediaPlayer;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);


    mediaPlayer = MediaPlayer.create(this, R.raw.laugh);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();


        }
    });
}


public void play(View view) {

    mediaPlayer.start();

}

public void pause(View view) {
    mediaPlayer.pause();
}