quarkus-tutorial (PostgreSQL Version)

This project uses Quarkus, the Supersonic Subatomic Java Framework. It is a slightly modified version of Julia Gustafsson's sample application built her freeCodeCamp tutorial "Getting Started with Quarkus and JPAStreamer" (see https://www.youtube.com/watch?v=KZnQ5R8Kd4I).

If you want to learn more about Quarkus, please visit its website: https://quarkus.io/ .

Prerequisites

• Java 11 or later
• Docker
• Pagila database running in a Docker container, see instructions here.

Changes to the original version

• adaptations to PostgreSQL-specific settings and data types
• changed request method of /update/{minLength}/{rentalRate} from @GET to @PUT (because a GET request shouldn't change data on the server)

Database

The application makes use of Pagila, a PostgreSQL-specific version of the Sakila Sample Database. I used PostgreSQL version 15.5 in this case, but other versions should be fine, too.

Class diagram

Running the application in dev mode

You can run your application in dev mode that enables live coding using:

./mvnw compile quarkus:dev

Running the application in dev mode

You can run your application in dev mode that enables live coding using:

./mvnw compile quarkus:dev

NOTE: Quarkus now ships with a Dev UI, which is available in dev mode only at http://localhost:8080/q/dev/.

NOTE: To test your endpoints using Swagger, visit http://localhost:8080/q/swagger-ui/[http://localhost:8080/q/swagger-ui/.

Packaging and running the application

The application can be packaged using:

./mvnw package

It produces the quarkus-run.jar file in the target/quarkus-app/ directory. Be aware that it’s not an über-jar as the dependencies are copied into the target/quarkus-app/lib/ directory.

The application is now runnable using java -jar target/quarkus-app/quarkus-run.jar.

If you want to build an über-jar, execute the following command:

./mvnw package -Dquarkus.package.type=uber-jar

The application, packaged as an über-jar, is now runnable using java -jar target/*-runner.jar.

Creating a native executable

You can create a native executable using:

./mvnw package -Dnative

Or, if you don't have GraalVM installed, you can run the native executable build in a container using:

./mvnw package -Dnative -Dquarkus.native.container-build=true

You can then execute your native executable with: ./target/quarkus-tutorial-1.0.0-SNAPSHOT-runner

Startup time comparison

non-native	native
0.928s	0.049s

Startup times taken on a Apple Silicon M2 Max with GraalVM for JDK 21.0.1. Pretty impressive, isn't it?

If you want to learn more about building native executables, please consult https://quarkus.io/guides/maven-tooling.

Related Guides

• JPAStreamer (guide): Express your Hibernate queries as standard Java Streams
• SmallRye OpenAPI (guide): Document your REST APIs with OpenAPI - comes with Swagger UI
• Hibernate ORM with Panache (guide): Simplify your persistence code for Hibernate ORM via the active record or the repository pattern
• JDBC Driver - PostgreSQL (guide): Connect to the PostgreSQL database via JDBC