Java - TP3

Multimedia player

Ideas of Questions:

• About Stream
• pitest
• Interface?

1 Instructions

This lab will be covered in practical sessions 3 and 4.

1.1 Launch service VSCode Java

• Restart the service from the last lab or Launch a new service VScode-Java

1.2 Update your repository

Perhaps the repository used as a template has been updated since the last practical session.

• Follow the commands given in Lab 2 to update your repository

1.3 Open Folder

In VSCode :

• File > Open Folder > tp3
  • or using: code-server ~/work/ENSAI-2A-Java-TP/tp3/

tp3 must be the root folder in your explorer.

1.4 When you’ve finished

• Save your work using git
• Pause or Delete your service

2 Subject

This exercise involves designing and implementing a media management system in Java. You’ll create classes for media types (songs, podcasts), playlists, and a media player. Focus on object-oriented principles, defining attributes, methods, and relationships. The goal is a functional system for managing and playing media.

Given files: Song.java and pom.xml

• Create the arborscence of a Maven project

3 Questions

3.1 Artist

In the Song class, we want to replace the String types for attributes singer, author, and composer with instances of an Artist class.

classDiagram

class Artist {
     - -firstName: String
     - -lastName: String
     - -nationality: String
     + toString(): String
}

In the toString() method, concat “Artist” with firstName and lastName.

• Create Artist class
• Refactor Song class updating attributes types
  • We’ll assume that the songs have a single singer, a single author, a single composer
• In Song class, create method play(),
  • this method will print each word of lyrics
  • use the code below to add a brief delay between each word

try {
    Thread.sleep(100);
} catch (InterruptedException e) {
    Thread.currentThread().interrupt();
    System.err.println("Thread was interrupted");
}

• Create a class Main with a main method
• In the main() method, create an instance of Song and play it
  • use a real Song, singer and lyrics
  • you are allowed to leave author and composer blank
  • for the lyrics, you can limit them to a few hundred words

3.2 Podcast

In your player you will also read Podcasts :

classDiagram

class Podcast {
    - -title: String
    - -host: String
    - -topic: String
    - -duration: int
    - -year: int
    - -subtitles: String
    + play()
}

• Implement class Podcast
  • Use OOP to avoid code duplication
• Create method play(), printing subtitles
  • Bonus: You will notice that this method is very similar to Song’s. Isn’t there a better way?
• Implement the toString() method in the same way as for songs

3.3 Pop, Rock, Electro

We want to add a new attribute to the Song to store the musical genres it is associated with.

• Create a structure to store musical genres
• Add 10 values of your choice
• Modify the Song class to add a list of musical genres to each song
• Don’t forget to update the main() method

3.4 Playlist

We now want to be able to create playlists with these songs and podcasts.

classDiagram

class Playlist {
    - -name: String
    - -mediaList: List~Media~
    - -totalDuration: int
    + addMedia(Media media)
    + removeMedia(Media media): bool
    + removeMedia(int index)
    + play(boolean random)
}

• Create a Playlist class with a name, a list of media and total duration
• Develop the addMedia() method to add a media at the end of the playlist
• Create the removeMedia(Media media) method
  • it deletes occurences of a media if it exists in the playlist
• Create unit tests with Junit for these last two methods
• Instanciate the removeMedia(Int i) method to delete a media by index
• Develop a method for playing the playlist
  • Include a parameter to play the tracks randomly
• Add the option of copying the playlist

3.5 Create some objects

In the main method:

• Create a new song (in addition to the one created at the beginning), as well as a Podcast
• Instantiate a playlist named p1 and add these three media to it
• Copy your playlist and name it p2
• Remove a song from p1
• Print the total duration of p1 and p2
• Play p2