MediaStore & ContentProviders in Android

 

useful videos & blogs : 

https://youtu.be/U5yDjBUSAic

ContentProvider & ContentResolver :

 https://youtu.be/-4GgzqMVrYc

https://youtu.be/eNW1d8tiXmQ

For API 23+ you need to request the read/write permissions even if they are already in your manifest.

while using mediaplayer to play audio, before we change the datasource using .setDataSource , we need to always reset the cursor.

//IMP TO RESET THE CURSOR , ELSE WONT PLAY ANOTHER AUDIOS.
mediaPlayer.reset();

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GET ALL THE AUDIO FILES ON THE EXTERNAL STORAGE

useful blog -https://medium.com/@sriramaripirala/android-10-open-failed-eacces-permission-denied-da8b630a89df

Add this if you are getting ERROR : open failed: EACCES (Permission denied)

<application android:requestLegacyExternalStorage="true" ... >

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"

Get permissions on the runTime.

    // asks a permission to the user.
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED){
        String[] permissions ={Manifest.permission.READ_EXTERNAL_STORAGE};
        ActivityCompat.requestPermissions(this,permissions,111);
    }else{
        loadSongs();
    }


}

// Called when a request permission is denied or accepted

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (requestCode==111 && grantResults[0]==PackageManager.PERMISSION_GRANTED){
        loadSongs();
    }
}

Song.java (Modal class )

package com.deepesh.mediaapp;

public class Song{

    String title;
    String author;
    String song_url;

    public Song(String title, String author, String song_url) {
        this.title = title;
        this.author = author;
        this.song_url = song_url;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public String getSong_url() {
        return song_url;
    }

    public void setSong_url(String song_url) {
        this.song_url = song_url;
    }
}

Loads all the Songs into a arraylist to display on a recyclerview.

// Gets all the audio files on the external storage & fills them inside the array
@RequiresApi(api = Build.VERSION_CODES.O)
private void loadSongs() {

    //songsList = new ArrayList<>();
    Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
    String selection = MediaStore.Audio.Media.IS_MUSIC+"!=0";

    Cursor cursor = getApplicationContext().getContentResolver()
                                    .query(uri,null,selection,null,null);

    if (cursor!=null){
        while (cursor.moveToNext()){
            String url = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DATA));
            String artist = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST));
            String title = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME));

            Song temp_song = new Song(title,artist,url);
            songsList.add(temp_song);

        }
    }
    assert cursor != null;
    // Dont Forget to close the cursor.
    cursor.close();
}

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