Lab 3: Music Library

Due: Sept 15, 11:59 pm PST

In this lab, we will develop a tool for helping to manage a music library. We'll focus at this point on representing and working with the metadata.

Later in the semester, we’ll hook this up to a server, to allow us to stream our music collection. This will also give you some practice with the following concepts:

• Creating a class diagram
• Tracing memory allocation
• Constructing classes and instances
• Using Lists
• Inheritance
• Unit testing
• Reading and writing from a file.

Rubric:
Complete, correct, conforming to style guides: full points.
Mostly complete, some style errors: -1.
Missing major parts: -2
Incomplete or not working: no credit.

setup

Recall from our initial design that we want to be able to:

• Organize our Library by Song, Artist, or Album
• Add or delete songs.
• Find songs by name, album or artist.
• Find duplicate songs
• Create a playlist
• Read and write our library to/from a file

Note: Task 1 and task 2 should be completed in a separate document, which should then be added to your repo. If you want to do either task on paper and then take a photo of it (and add that to your repo), that's fine also.

Task 1 (4 points)

Complete the class design that we started in class to include a Library and a Playlist class. Indicate any additional isA and hasA relationships.

Task 2 (4 points)

Trace by hand the following simplified version of our classes. You can assume that all classes have a default constructor that allocates their members to 0, and empty String, or an empty ArrayList;:

public class Song {
    String name;
    Artist artist;
    int timesPlayed;
}
public class Artist {
    String name;
    ArrayList<Songs> songs;
    ArrayList<Album> albums;
}
public class Album {
    String name;
    Artist artist;
    ArrayList<Song> songs;
}

Song s1, s2, s3;
Artist a1;
Album album1, album2;
s1= new Song();
s2 = new Song();
Artist a1 = new Artist();

a1.name = "The Beatles";
s1.name = "Here Comes The Sun";
s1.artist = a1;
a1.songs.add(s1);
s2.name = "Tomorrow Never Knows";
s2.artist = a1;
a1.songs.add(s2);
s3 = new Song();
s3.name = "Something";
s3.artist = a1;
a1.songs.add(s3);
album1 = new Album();
album1.name="Abbey Road";
album1.songs.add(s1);
album1.songs.add(s3);
a1.albums.add(album1);
album1.name="Revolver";
album1.songs.add(s2);
a1.albums.add(album2);

Task 3 (4 points)

Implement the Song, Artist, Album and Entity classes, including constructors, setters/getters, equals(), and toString();

Task 4. (4 points)

Create unit tests for each of these classes. You can test all of the classes within one test program if you like.

Task 5. (5 points)

Implement the Library class, completing the constructor, setter/getters and methods findAlbum(), findArtist(), findSong(), add(), delete(), display(), and findDuplicate();

Add unit tests for each of these methods.

Task 6 (5 points)

Implement the Playlist class. Add setters/getters, and complete the methods add(), remove() and shuffle(); Add unit tests for each of these.

Task 7 (4 points)

Complete the readFromFile() and writeToFile() methods in the Library class.