Play Audio using MediaPlayer in Android

A MediaPlayer allows playing audio in Android application. Audio can be played from various sources, such as app's resources, external storage, from the internet.

In the layout XML file, we added two Button elements that will be used to control audio playback.

app/src/main/res/layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/startButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Start" />

    <Button
        android:id="@+id/stopButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Stop" />

</LinearLayout>

Under the res directory, create a new raw resource directory. Put the audio file into the raw directory.

app/src/main/res/raw/audio.mp3

We created an instance of MediaPlayer and set the URI of the audio.

The player for playback is prepared by using the prepare() method. When the application is stopped, we release resources associated with an instance of MediaPlayer by using release() method.

app/src/main/java/com/example/app/MainActivity.kt

package com.example.app

import android.media.MediaPlayer
import android.net.Uri
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity()
{
    private lateinit var mediaPlayer: MediaPlayer

    override fun onCreate(savedInstanceState: Bundle?)
    {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val path = "android.resource://" + packageName + "/" + R.raw.audio

        mediaPlayer = MediaPlayer()
        mediaPlayer.setDataSource(this, Uri.parse(path))

        startButton.setOnClickListener {
            if (!mediaPlayer.isPlaying) {
                mediaPlayer.prepare()
                mediaPlayer.start()
            }
        }
        stopButton.setOnClickListener {
            if (mediaPlayer.isPlaying) {
                mediaPlayer.stop()
            }
        }
    }

    override fun onStop()
    {
        mediaPlayer.release()
        super.onStop()
    }
}