Create albums out of songs

I have made a method which returns a list of all songs on my device. Now I want to get a list of albums out of these songs.

What I basically do is go through every song I have in my list, check if its album is already in the list and if not I create a new album.

This method will take some time since there are 1400 songs on my device so I wondered how I can make this method any faster? Also, any other improvements?

public static ArrayList loadAlbums( Context c ){
    ArrayList tmpList = getAllSongs( c);
    ArrayList albumList = new ArrayList();

    for( Song s : tmpList ){

        boolean added = false;

        for( Album a : albumList ){

            if( a.getAlbumName().contentEquals( s.getAlbum() ) && a.getArtistName().contentEquals( s.getArtist() ) ){
                a.addSong( s.getPath() );
                added = true;
            }
        }

        if( !added ){
            Album a = new Album( s.getAlbum() );
            a.setAlbum_id( s.getAlbumId() );
            a.setArtistName( s.getArtist() );
            a.addSong( s.getPath() );

            albumList.add(a);
        }

    }

    tmpList = null;
    return albumList;
}

What you need is a Map. A map is a collection of key --> value combinations. There can not be two equal keys pointing to different values.

There are a few ways to organize this map. The simplest is to make Map albumNames;, but that would make it possible for collisions if two albums had the same album name.

Another alternative is Map> for fixing the problem with albums having the same name.

There are more alternatives but they can get quite complex so I think this is enough for now.

Then when you loop through your songs, for each song:

• List possibleAlbums = albumNames.get(song.getAlbum()).

• If that returns null, then add a new list and add an album to it.

• otherwise loop through the list to find the album you are looking for (that matches the artist). Again, if none is found create a new one.

• Once you have found or created a matching album, you can add the song to it.

Other comments:

-
Declare by interface and not implementation. Make the method return List, also use for example List tmpList = getAllSongs(c);

-
Use longer and better names. s --> song, a --> album, c --> context, tmpList --> songs.

-
tmpList = null; in the bottom of the method will have no effect whatsoever. You can safely remove that line.

StackExchange Code Review Q#56548, answer score: 10