ByEnrique Kessler Martínez|
December 21, 2020
808 words
3 minutes

AppMusic was one of the first projects that I embarked on with other developers. It is a Maven music player desktop app that has been created with some cool functionality. It was created using the Spring framework, using Java11 and structuring the development with Maven. With AppMusic you are able to:


The structure of AppMusic can be appreciated in the subsequent image:


The Persistence was configured using the H2 engine, which provides with the possibility to register entities, and allows for editing certain values of the mentioned entities. The important information regarding the H2 documentation can be found at:


The UI was created using the Swing Framework. Swing allows for different elements which composes every "view". The views in our app are composed of JFrame, which may or may not have different pannels inside, containing the relevant "Components". Examples of the views:

Search Songs🔍

You have the possibility to access the the search songs tab, which allows you to access all the songs that have been persisted and play a certain one. You could also play songs by double clicking them in this tab. The search possibilities are with the following sections:

  • Genre: Genres are calculated dinamically with the keys read while parsing the xml files.
  • Artist: Search by the name of the artist.
  • Title: Search by the name of the song.

Recent Songs🔁

The Recent songs tab is the default tab when you enter the app and contains the list of the 10 recently played songs. You could still access the media functionality.


Following the functionality list, playlist functionality has been implemented. While being a normal user, you have access to creation of ilimited playlists (New Playlist Tab) and media functionality for your created playlists on the My Lists Tab.

If you upgraded your account (fictional upgrade), you would be applied a discount code depending on defined codes being applicable. When multiple codes are applicable, the highest discount is applied.


AppMusic was designed having the Design Patterns book by Gang of Four in mind.

Starting with the patterns used, is the MVC pattern, which is creating a Controller that asures that we have layer separation between models and UI elements in the application. We also make use of the DAO pattern, which is used to make the application independent of any persistence framework.

In order to implement the Discount functionality we use the Strategy pattern, which allows for dynamic and execution time changing on the implementation for Discounts. The Discount interface is defined, which will be implemented by concrete Discount classes like "EducationDiscount" or "ElderDiscount".

The Singleton pattern is used in order to provide our factories —which are the classes that store the persisted elemements in HashMaps in order to allow for faster access— with only one instance in the entire application, reducing overhead by creation of objects. We use the implementation model of declaring a getInstance method that checks whether the instance attribute is non-null and returns it. If the instance is null, it calls the private constructor to create the new instance.

Lastly, we use the Observer pattern so that our Controller can listen to any possible changes on the Song Component, which provides a list of Songs that it parses from an xml file. Any possible change in the list is notified to all the listeners, which in this case is only the Controller.


This instructions will get you up and running for development purposes. See Tests for notes on how to test the app and special requests on tests created.


As you can see in the description of the project, we use Maven in order to provide for easier control of the project, hence the need of installing Maven. You can install it reaching the following link and reading the installing steps for your OS distribution.

As a side note, we use —in order to comply with instructions from professors— the H2 persistence system, adapted to our course. You should be able to get it googling for H2 server or use your own persistence framework, like SQLite3.

Getting up and running

1. Fork this repository.
2. Clone the repo that you just forked, ⚠ IMPORTANT to clone the repo that you just forked, not this one, you should go to your Github profile if necessary.
3. Checkout to the "dev" branch, at AppMusic we use GitFlow.

   git checkout dev

4. Create a new branch off the "dev" branch:

   git checkout -b <new_branch_name>

5. Run mvn install in order to install all the dependencies.

   mvn install

6. Open the persistence server.
7. Run the App class, which contains the main function for the application.

You are up and running! Enjoy!


We use JUnit4 in order to provide tests to the application. Any functionality that is pull requested should have the according tests in order to make sure that everything is working and integrated correctly with other functionality.

Maven provides the easy mvn test command, which runs the test suite for the application.


This project is licensed under the MIT Licence - see the LICENSE file for details.