Vaadin + Spring Boot + MongoDB + MariaDB MaxScale demo

This example shows how to connect a Vaadin application to MongoDB databases. This file also shows how to use MaxScale to connect the same application to a MariaDB backend using the NoSQL protocol without modifying the app.

Preparing the database

You need MongoDB listening on port 27017 or a MariaDB database and a MaxScale instance.

Setting up the database cluster using Docker

Clone the following repository which contains Docker files to set up MariaDB replication and MaxScale:

git clone https://github.com/alejandro-du/mariadb-docker-deployments.git

Build the images (don't use these in production environments):

cd mariadb-docker-deployments
docker build --file single-node/Dockerfile --tag alejandrodu/mariadb-single-node .
docker build --file primary/Dockerfile --tag alejandrodu/mariadb-primary .
docker build --file replica/Dockerfile --tag alejandrodu/mariadb-replica .
docker build --file maxscale/Dockerfile --tag alejandrodu/mariadb-maxscale .

Alternatively, you can use the build.sh script if you are on Linux.

Run the containers:

docker compose up -d

Run the web application

Clone this repository:

git clone https://github.com/alejandro-du/mongodb-vaadin-demo.git

Build the Java web application using Maven:

cd mongodb-vaadin-demo
mvn package

Run the application:

java -jar target/mongodb-vaadin-demo.jar

Access the application in your browser at http://localhost:9090. Insert some data.

Access the MaxScale GUI at http://localhost:8989/ using the following credentials:

• Username: admin
• Password: mariadb

In the menu, go to the query editor and connect to the database using:

• Listener name: query_router_listener
• Username: user
• Password: password

Inspect the database and query the student table:

select * from student

Or use MariaDB's JSON functions:

select
	json_value(doc, '$.firstName') as firstName,
	json_value(doc, '$.lastName') as lastName
from student

To shutdown the database cluster run:

docker compose down

Add -v to the above command if you want to remove the related Docker volumes as well (you'll lose all the configuration and data).