# ddd-cqrs-4-java-example
Example applications and microservices that use [ddd-4-java](https://github.com/fuinorg/ddd-4-java) and [cqrs-4-java](https://github.com/fuinorg/cqrs-4-java) libraries and an [EventStore](https://eventstore.org/) to store the events (Event Sourcing).

## Components
- **[Shared](shared)** - Common code for all demo applications (commands, events, value objects and utilities).
- **[Aggregates](aggregates)** - DDD related code for all demo applications (aggregates, entities and business exceptions).
- **[Quarkus](quarkus)** - Two microservices (Command & Query) based on [Quarkus](https://quarkus.io/).
- **[Spring Boot](spring-boot)** - Two microservices (Command & Query) based on [Spring Boot](https://spring.io/projects/spring-boot/).
- **[Java SE + CDI](java-se-cdi)** - Two standalone applications (Command & Query) using CDI for dependency injection.

## Getting started

### Prerequisites
#### Install everything yourself (Option 1) 
Make sure you have the following tools installed/configured:
* [git](https://git-scm.com/) (VCS)
* [Docker CE](https://docs.docker.com/engine/installation/linux/docker-ce/ubuntu/)
* [Docker Compose](https://docs.docker.com/compose/)
* *OPTIONAL* [GraalVM](https://www.graalvm.org/)
* Hostname should be set in /etc/hosts (See [Find and Change Your Hostname in Ubuntu](https://helpdeskgeek.com/linux-tips/find-and-change-your-hostname-in-ubuntu/) for more information)

#### Use lubuntu-developer-vm (Option 2)
The **[lubuntu-developer-vm](https://github.com/fuinorg/lubuntu-developer-vm)** has already (almost) everything installed. You only need to  execute the following steps:
1. Download and install the [lubuntu-developer-vm](https://github.com/fuinorg/lubuntu-developer-vm) as described
2. OPTIONAL: Change memory of VM to 6 GB (instead of 4 GB default) if you want to create a native image with GraalVM 
3. Start the VM and login (developer / developer)
4. Open a console (Shortcut = ctrl alt t)
5. Run a script that finalizes the setup of the developer virtual machine
   ```
   bash <(curl \
   -s https://raw.githubusercontent.com/fuinorg/ddd-cqrs-4-java-example/master/setup-lubuntu-developer-vm.sh)   
   ```
6. Reboot
   ```
   reboot
   ```

### Clone and install project 
1. Open a console (Ubuntu shortcut = ctrl alt t)
2. Clone the git repository
   ```
   git clone https://github.com/fuinorg/ddd-cqrs-4-java-example.git
   ```
3. Change into the project's directory and run a Maven build
   ```
   cd ddd-cqrs-4-java-example
   ./mvnw install
   ```
   Be patient - This may take a while (~5 minutes) as all dependencies and some Docker images must be downloaded and also some integration tests will be executed.
   
### Start Event Store and Maria DB
1. Open a console (Ubuntu shortcut = ctrl alt t)
2. Change into the project's directory and run Docker Compose
   ```
   cd ddd-cqrs-4-java-example
   docker-compose up
   ```

### Start command / query implementations
Start one command and one query microservice. 

- Quarkus Microservices
  - [Command](quarkus/command)
  - [Query](quarkus/query)
  
- Spring Boot Microservices
  - [Command](spring-boot/command)
  - [Query](spring-boot/query)

### Test
1. Open [http://localhost:2113/](http://localhost:2113/) to access the event store UI (User: admin / Password: changeit)
   You should see a projection named "qry-person-stream" when you click on "Projections" in the top menu.
2. Opening [http://localhost:8080/persons](http://localhost:8080/persons) should show an empty JSON array
3. Open a console (Ubuntu shortcut = ctrl alt t)
4. Change into the demo directory and execute a command using cURL (See [shell script](demo/create-person-command.sh) and [command](demo/create-person-command.json)) 
   ```
   cd ddd-cqrs-4-java-example/demo
   ./create-person-command.sh
   ```   
   Command console should show something like
   ```
   Update aggregate: id=PERSON 84565d62-115e-4502-b7c9-38ad69c64b05, version=-1, nextVersion=0
   ```   
   Query console should show something like
   ```
   PersonCreatedEventHandler ... Handle PersonCreatedEvent: Person 'Peter Parker' was created
   ```    
4. Refreshing [http://localhost:8080/persons](http://localhost:8080/persons) should show
    ```json
    [{"id":"84565d62-115e-4502-b7c9-38ad69c64b05","name":"Peter Parker"}]
    ```
5. Opening [http://localhost:8080/persons/84565d62-115e-4502-b7c9-38ad69c64b05](http://localhost:8080/persons/84565d62-115e-4502-b7c9-38ad69c64b05) should show
    ```json
    {"id":"84565d62-115e-4502-b7c9-38ad69c64b05","name":"Peter Parker"}

### Stop Event Store and Maria DB and clean up
1. Stop Docker Compose (Ubuntu shortcut = ctrl c)
2. Remove Docker Compose container
   ```   
   docker-compose rm
   ```