Java - TP3

Rated TP
Author

Ludovic Deneuville

1 Instructions

  • Groups of 1 or 2 students (from the same TP group)
    • Edit the README.md (when it’s created) file to enter your names
    • Inter-group plagiarism will be severely punished
  • Due Date: Wednesday 26 March at 10pm
    • 1 point deducted for each half-hour delay
  • Zip your project repository and load it on Moodle
    • Don’t include target folder

Your code must be functional, with no compilation or runtime errors.

Don’t forget to include the javadoc and to comment your code if necessary.

Important
  • Everything you need is in the course and the practical exercises
  • You are permitted to conduct internet searches to find information and documentation
  • The use of any LLM is strictly prohibited during this exam
    • As Olivier so rightly says: LLMs are good servants, but bad masters
    • They can be useful tools, but they must not replace your own comprehension and programming skills

If you are caught using an LLM, it will be considered cheating and you will receive a zero.

1.1 Create a private repo

    • Repository name: ENSAI-Java-TP3
    • Private
    • ✅ Add a README file
    • Add .gitignore: Java
    • Licence: Apache License 2.0 (or another)

1.2 Launch service VSCode Java

Caution

Service interruptions are possible. To prevent data loss, back up your code regularly with Git.

After each part, create a commit and push your code to the remote repository.

1.3 When you’ve finished

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
  • pom.xml
Song.java
package fr.ensai.mediaplayer;

/**
 * Represents a song with essential attributes.
 */
public class Song {
    private String singer;
    private String title;
    private int year;
    private int duration;
    private String lyrics;
    private String author;
    private String composer;

    /**
     * Constructs a new Song object.
     *
     * @param title    The title of the song.
     * @param singer   The singer of the song.
     * @param title    The title of the song.
     * @param year     The year the song was released.
     * @param duration The duration of the song in seconds.
     * @param lyrics   The lyrics of the song.
     * @param author   The author of the song.
     * @param composer The composer of the song.
     */
    public Song(String title, String singer, int year, int duration, String lyrics, String author, String composer) {
        this.title = title;
        this.singer = singer;
        this.year = year;
        this.duration = duration;
        this.lyrics = lyrics;
        this.author = author;
        this.composer = composer;
    }

    /**
     * String representation of the Song.
     */
    @Override
    public String toString() {
        return "Song " + this.title + " by " + this.singer;
    }
    
    /**
     * Indicates whether some other object is "equal to" this one. Two Song
     * objects are considered equal if they have the same title, singer, and year.
     */
    @Override
    public boolean equals(Object o) {
        if (this == o)
            return true;
        if (o == null || this.getClass() != o.getClass())
            return false;
        Song otherSong = (Song) o;
        return this.year == otherSong.year &&
                Objects.equals(this.title, otherSong.title) &&
                Objects.equals(this.singer, otherSong.singer);
    }

    @Override
    public int hashCode() {
        return Objects.hash(this.title, this.singer, this.year);
    }

}
pom.mxl
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>fr.ensai</groupId>
    <artifactId>mediaplayer</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
    </properties>

    <dependencies>
        <!-- JUnit for testing -->
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>5.9.1</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>5.9.1</version>
            <scope>test</scope>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <!-- Compiler Plugin -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>21</source>
                    <target>21</target>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>3.0.0</version>
                <configuration>
                    <mainClass>fr.ensai.mediaplayer.Main</mainClass>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>3.2.5</version>
            </plugin>
        </plugins>
    </build>
</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.

    • We’ll assume that the songs have a single singer, a single author, a single composer
    • 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");
}
    • 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()
}

    • Use OOP to avoid code duplication

3.3 Pop, Rock, Electro

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

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)
}

    • it deletes occurences of a media if it exists in the playlist
    • Include a parameter to play the tracks randomly

3.5 Create some objects

In the main method: