Introduction

Helidon is a Java framework for building cloud-native applications. It provides APIs and runtime services for creating standalone applications that are easy to develop, deploy, observe, and scale.

Helidon MP adds a MicroProfile programming model on top of Helidon. It supports MicroProfile and Jakarta EE APIs, uses annotation-driven components with dependency injection, and gives developers a familiar way to build REST services, configuration, security, health checks, metrics, and other microservice features.

Helidon MP applications run as standalone JVM processes, are powered by the Helidon WebServer, and use Java 21 virtual threads throughout the WebServer.

Strengths

• MicroProfile APIs for common microservice concerns.

• Jakarta EE annotations for REST services and data access.

• Dependency injection for composing application components.

• Standalone JVM applications with no application server dependency.

• High-concurrency services that benefit from virtual threads.

• Helidon WebServer runtime with cloud-native observability.

First Look

A Helidon MP application can expose a REST endpoint using Jakarta RESTful Web Services annotations:

@Path("hello")
public class HelloWorld {
    @GET
    public String hello() {
        return "Hello World";
    }
}