Micronaut

Aravindan Mathiazhagan

Published in

DigIO Australia

3 min readAug 8, 2020

Ahead-of-Time Compilation ( simple and fast )

Micronaut is a JVM based framework for building

Lightweight Modular and easily testable application
Fast startup and low memory consumption Microservice
Serverless Functions
Command line application
Android application

It was developed by same team who developed Grails, which become open source under Apache on 23 May 2018.

Features

Optimise start-up time
Reduce memory footprint
Not bound to the size of your codebase.
Build AOP proxies at compile time that are completely reflection free, which improves performances
Reduces stack trace sizes and reduces memory consumption.
Micronaut functions can be deployed to either AWS lambda or any FaaS platform that can execute the function as a container.
Designed with Microservice and cloud computing in mind

Supports

Java, Kotlin, and Groovy development
Maven and Gradle as build tools.
Can run on GraalVM, JVM
Non blocking reactive HTTP client and server API’s
Security using JWT and OAuth2
Service discovery eg. Eureka, Consul
API versioning via a dedicated @ Version
Micronaut for Spring

Micronaut vs Spring

Reactive HTTP client and server (based on Netty). adds the ability to use Spring annotation-based programming model to build Micronaut applications

Compile-time AOP and dependency injection
Distributed tracing and logging eg. Zipkin, Jaeger
Scalability and load balancing
API documentation using OpenAPI
It is resilient - built-in support for retry, circuit breaker and fallbacks
Builds its dependency injection data at compile time, which, of course, is much faster than reflection-based runtime dependency injection. It uses JSR-330 (java.inject) for doing it.
Suits cloud-native features.
Built-in support for generating Open API / Swagger YAML documentation at compilation time

Startup Time

First Response Time

Micronaut CLI

mn create-app hello-world-app -build gradlemn create-controller -lang kotlin accountmn create-app my-demo-app — features mongo-reactivemn profile-info service