Learn QUARKUS with Real Code Examples

Quarkus provides a modern framework for Java developers targeting cloud, microservices, and serverless architectures.

Optimized for GraalVM and HotSpot for fast startup and low memory footprint.

Supports reactive programming and imperative APIs.

Includes live reload for rapid development cycles.

Ideal for microservices, RESTful APIs, and event-driven applications.

RESTful API development with JAX-RS

Dependency injection with CDI

Reactive streams and non-blocking I/O

Integration with databases via Panache

Cloud-native features like Kubernetes/OpenShift integration

Quarkus application – core project structure

Endpoints – REST APIs using JAX-RS

CDI Beans – dependency-injected components

Reactive components – event-driven programming

Extensions – modular integrations for DB, messaging, etc.

src/main/java - application code

src/main/resources - configuration files

src/test/java - unit and integration tests

pom.xml / build.gradle - project configuration

extensions/ - modular integrations via Quarkus extensions

Create Quarkus project using CLI or Maven/Gradle

Define REST endpoints with `@Path` and `@GET/POST`

Inject dependencies with `@Inject`

Add extensions for database, messaging, or security

Run in dev mode with hot reload for rapid iteration

Beginner: simple REST endpoint

Intermediate: CRUD APIs with Panache ORM

Advanced: reactive microservices with Kafka/RabbitMQ

Expert: native image deployment with GraalVM

Auditor: performance tuning and monitoring

Quarkus vs Spring Boot: Quarkus faster startup and lower memory; Spring Boot more mature ecosystem

Quarkus vs Micronaut: Both cloud-native; Quarkus has more Red Hat support

Quarkus vs Vert.x: Vert.x is low-level reactive toolkit; Quarkus offers full-stack features

Quarkus vs Helidon: Helidon is micro-profile based; Quarkus emphasizes native images

Quarkus vs Node.js (Fastify): Java ecosystem vs Node.js, strong typing vs JS flexibility

2019 – Quarkus initial release by Red Hat

2020 – Native image support and reactive programming enhancements

2021 – Expanded extension ecosystem and cloud-native integrations

2022 – Kubernetes/OpenShift optimizations

2023–2025 – Improved developer tools, GraalVM optimizations, and cloud-native support

Quarkus app - core Java application instance

Endpoint - REST API path

CDI Bean - dependency-injected component

Extension - modular integration (DB, messaging, security)

Mutiny - reactive programming library