aarnone / gamerental

Sample Game Rental application show casing Axon

Game Rental Application

Description

The "Game Rental" application showcases how Axon Framework and Axon Server can be used during software development. The domain which is focused on is that of rental services from the perspective of a video game store.

This repository provides just such an application, albeit a demo rather than a full fledged solution. It serves a personal purpose of having a stepping stone application to live code during application. My intent is to build upon this sample during consecutive talks, further enhancing its capabilities and implementation as time progresses. For others, I hope this provides a simple and quick look into what it means to build an Axon-based application.

Due to its nature of being based on Axon, it will incorporate DDD, CQRS, Event Sourcing, and an overall messaging solution to communicate between distinct components.

Project Traversal

Distinct branches will be (made) available per public speaking, sharing a start and final solution branch separately. Additionally, several branches representing the steps throughout the lifecycle of the "Game Rental" application will be present, allowing you to:

• Check out the exact step you are interested in.
• Perform a git reset --hard step# to reset your current branch.

Next to providing the convenience of showing the flow, it also serves the purpose of being a back-up during the presentation.

The following steps have been defined for this project:

1. The core-api, containing the commands, events, queries and query responses.
2. The command model has been created, showing a Game aggregate.
3. The application connects to Axon Cloud, through the added Axon Server properties to the application.properties.
4. The query model, a GameView, is provided, created/updated and made queryable through the GameCatalogProjector.
5. The Reactor Extension is included and used by the GameRentalController.
6. Cleaner distributed exceptional handling is introduced, through an ExceptionStatusCode specific exception being thrown in @ExceptionHandler annotated functions in the Game aggregate and GameCatalogProjector.

Running and testing the application

As this is a Spring Boot application, simply running the GameRentalApplication is sufficient. Granted that a connection is made with an Axon Server instance. Ideally Axon Cloud is used for this, as is shown in step 3. If you desire to run Axon Server locally, you can download it here.

To validate the inner workings of the app, two .http files have been provided to the root folder of this project. The register-games.http allows for the registration of several games, to build a base catalog. The other-requests.http can be used to test out all other operations.