Audio Player

This is an Android application that allows user to search for songs by title and play songs with default music player in the device.

This application uses the following features of Android.

MediaStore to get access to songs in external storage
Shows how to take runtime permission for external storage if run in device with API >= 23
SimpleAdapter with ListView to display songs
Intent to invoke built in Music player of the device
onRestoreInstanceState() to redisplay the list of songs when Activity is recreated

Steps

Here are the steps and code related to this application.

First create a new Android project that supports API 10 or above. I named it as AudioPlayer

Create Song class that represents a song as shown below:

Song.java

package com.st.media;
public class Song  {
     private String title;
     private String duration;
     private String singer;
     private String filename;
     
	public String getFilename() {
		return filename;
	}
	public void setFilename(String filename) {
		this.filename = filename;
	}
	public String getTitle() {
		return title;
	}
	public void setTitle(String title) {
		this.title = title;
	}
	public String getDuration() {
		return duration;
	}
	public void setDuration(String duration) {
		this.duration = duration;
	}
	public String getSinger() {
		return singer;
	}
	public void setSinger(String singer) {
		this.singer = singer;
	}
}

Create layout that represents a song. This layout is used by ListView when it displays song.

song.xml

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

    <TextView android:id="@+id/textTitle" android:layout_width="wrap_content"
        android:textColor="#0000ff"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:layout_height="wrap_content" android:text="TextView" />


    <TextView android:id="@+id/textSinger" android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:text="" />

    <TextView android:id="@+id/textDuration" android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:text="" />

</LinearLayout>

Create layout for AudioPlayer Activity

activity_audio_player.xml

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

    <LinearLayout  android:layout_width="match_parent"
        android:layout_height="wrap_content"  android:orientation="horizontal">
        <TextView
            android:id="@+id/textView1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Song Title :" />
        <EditText
            android:id="@+id/editTitle"
            android:layout_width="wrap_content"
            android:layout_weight="1"
            android:layout_height="wrap_content">
            <requestFocus />
        </EditText>
        <Button
            android:id="@+id/btnSearch"
            android:onClick="searchSongs"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Search" >
        </Button>
    </LinearLayout>
    <LinearLayout  android:layout_width="match_parent" android:id="@+id/songsView"
        android:layout_height="match_parent"  android:orientation="vertical">
        <TextView
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:text="List Of Songs"
            android:textColor="#ff0000"
            android:textStyle="bold"
            android:textSize="20sp" />
        <ListView
            android:id="@+id/listSongs"
            android:layout_width="match_parent"
            android:layout_weight="1"
            android:layout_height="match_parent" >
        </ListView>
    </LinearLayout>
</LinearLayout>

Write code for AudioPlayer Activity

AudioPlayerActivity.java


package com.st.media;

import android.Manifest;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

public class AudioPlayerActivity extends Activity {
    ListView listSongs;
    ArrayList<Song> songs;
    EditText editTitle;
    LinearLayout songsView;
    final int STORAGE_PERMISSION = 1;
    boolean permissionGranted  = false;

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        // search for songs on restore
        searchSongs(null);
    }

    @Override
    public void onCreate(Bundle state) {
        super.onCreate(state);
        setContentView(R.layout.activity_audio_player);

        // get the list of files and place them in ListView
        listSongs = (ListView) this.findViewById(R.id.listSongs);
        editTitle = (EditText) this.findViewById(R.id.editTitle);
        songsView = (LinearLayout) this.findViewById(R.id.songsView);
        songsView.setVisibility(View.INVISIBLE);

        listSongs.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> view, View item, int position, long id) {
                // Play song using  built-in audio player
                String filename = songs.get(position).getFilename();
                Uri audio = Uri.parse("file://" +filename);
                Intent intent = new Intent(Intent.ACTION_VIEW);
                intent.setDataAndType(audio, "audio/*");
                startActivity(intent);
            }
        });

        // Need to take permission at runtime if API is >= 23
        if ( Build.VERSION.SDK_INT>= 23) {
            if (checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, STORAGE_PERMISSION);
            }
            else
            {
                permissionGranted = true;
            }
        }
    }

    // Called after user responds to permission request
    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
       if ( requestCode ==  STORAGE_PERMISSION)
       {
           if ( grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
               permissionGranted = true;
           else
               permissionGranted = false;
       }
    }

    public void searchSongs(View v) {
        if (!permissionGranted  && v != null)
        {
            Toast.makeText(this,"Sorry! You don't have permission to read storage!", Toast.LENGTH_LONG).show();
            return;
        }
        // This is on restore. So just do nothing and return
        if ( v == null && !permissionGranted)
            return;

        bindSongsToListView(editTitle.getText().toString());
        if (songs.size() > 0)
            songsView.setVisibility(View.VISIBLE);
        else
            songsView.setVisibility(View.INVISIBLE);
    }

    private void bindSongsToListView(String title) {
        songs = new ArrayList<Song>();
        Cursor cursor = getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null,
                           MediaStore.Audio.Media.TITLE + " like  ? ",
                           new String[] { "%"  + title + "%"}, null);
        ArrayList<Map<String,String>> songsList = new ArrayList< Map<String,String>>();

        while (cursor.moveToNext()) {
            Song s = new Song();
            s.setFilename(cursor.getString(cursor.getColumnIndex( MediaStore.Audio.Media.DATA)));
            s.setTitle( cursor.getString(cursor.getColumnIndex( MediaStore.Audio.Media.TITLE)));
            long duration =  cursor.getLong(cursor.getColumnIndex( MediaStore.Audio.Media.DURATION));

            s.setDuration( String.format("%5.2f Mins", (duration / 1000.0) / 60));
            s.setSinger( cursor.getString(cursor.getColumnIndex( MediaStore.Audio.Media.ARTIST)));
            songs.add(s);

            Map<String, String> mapobject = convertSongToMap(s);
            songsList.add(mapobject);
        }


        SimpleAdapter adapter = new SimpleAdapter(this, songsList, R.layout.song,
                new String[]{"title", "duration", "singer"},
                new int[]{R.id.textTitle, R.id.textDuration, R.id.textSinger});

        listSongs.setAdapter(adapter);
    }

    public Map<String, String> convertSongToMap(Song s) {

        HashMap<String, String> map = new HashMap<String, String>();
        map.put("title", s.getTitle());
        map.put("duration", s.getDuration());
        map.put("singer", s.getSinger());
        return map;
    }
}

Modify manifest to start with AudioPlayerAcivity and list required permissions

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.st.media">
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".AudioPlayerActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
   </application>
</manifest>

Ensure you place some .MP3 songs loaded into your device
Build and run the project using Emulator that supports Android 2.3 (API 10) or higher
Enter string that you want to find in song title and click on Search button. When the selected songs list is displayed, click on the song to play it.