Helidon: A Modular Approach to Java Development

In the realm of Java development, monolithic applications are slowly becoming a relic of the past. The microservices architecture, with its focus on modularity, scalability, and independent deployments, has taken center stage. This is where Helidon emerges as a powerful framework, empowering you to build modern, robust microservices applications with a unique twist – modularity.

Unlike some monolithic frameworks that enforce a specific development style, Helidon embraces a modular approach. It provides a collection of core libraries that you can mix and match to build your microservices exactly the way you need them. This flexibility allows you to leverage only the functionalities you require, keeping your applications lean and efficient.

This article delves into the core concepts of Helidon, explores its modular architecture, and unveils the benefits it brings to your Java development endeavors.

1. Embracing Modularity in the Microservices Era

The landscape of Java development is undergoing a significant shift. Monolithic applications, while once dominant, are struggling to keep pace with the demands of modern software. Enter microservices architecture, a revolutionary approach that has taken the Java world by storm.

Microservices architecture decomposes an application into smaller, independent services. Each service focuses on a specific business capability, fostering modularity, scalability, and faster development cycles. Imagine a large monolithic application as a single, complex machine. Microservices break it down into smaller, specialized tools that work together seamlessly.

This shift towards microservices necessitates robust frameworks to streamline development. Helidon emerges as a compelling solution, offering a unique advantage – a modular approach. Unlike some frameworks that dictate a specific development style, Helidon embraces flexibility. It provides a collection of core libraries that you can mix and match to construct your microservices precisely how you envision them.

Think of Helidon’s core libraries as building blocks. Need web service functionalities? Helidon SE (Jakarta Servlet API) has you covered. Building asynchronous applications? Helidon Reactive provides the tools you need. It doesn’t force you to use everything; it empowers you to choose only the functionalities your microservices require. This modularity keeps your applications lean, efficient, and perfectly tailored to your specific needs.

In the following sections, we’ll delve deeper into the core concepts of Helidon, explore the advantages of its modular approach, and discover how it can empower you to build modern, robust microservices applications in Java.

2. Core Concepts of Helidon

Helidon’s modularity shines through its core libraries, each catering to specific functionalities within your microservices. Let’s explore some of these key building blocks:

• Helidon SE (Jakarta Servlet API): This library provides a foundation for building web services using the Jakarta Servlet API (formerly Java Servlet API). If your microservice needs to handle HTTP requests and responses, Helidon SE offers a familiar and well-established approach. You can find more information about the Jakarta Servlet API here:
• Helidon Reactive: The power of asynchronous programming is harnessed through Helidon Reactive. This library leverages technologies like Project Reactor to enable non-blocking I/O operations, making your microservices more responsive and efficient under heavy workloads. Imagine handling multiple requests concurrently without your application grinding to a halt – that’s the beauty of reactive programming.
• Helidon Microprofile: Microservices thrive on standards and interoperability. Helidon Microprofile ensures your services adhere to the Microprofile specifications, a set of standards designed to simplify microservices development and promote communication between services from different vendors. Think of it as a common language for your microservices to understand each other seamlessly.

These are just a few core Helidon libraries, with others available for specific functionalities like security and configuration management (Config). The beauty lies in the freedom to choose the libraries that align perfectly with your microservice’s needs.

Helidon Stacks: Pre-built Convenience

While individual libraries offer granular control, Helidon acknowledges that some use cases have common requirements. This is where Helidon Stacks come into play. These pre-configured combinations of core libraries provide a convenient starting point for building specific types of microservices.

Here are some examples of Helidon Stacks:

• Webserver: This stack includes Helidon SE, offering a basic foundation for building web services.
• Reactive: This stack focuses on asynchronous programming with Helidon Reactive as the core component.
• Webserver + Reactive: This stack combines both Helidon SE and Helidon Reactive, providing a powerful foundation for building reactive web services.

Helidon Stacks eliminate the need to assemble libraries from scratch for common use cases. This streamlines development and allows you to focus on the unique logic of your microservice. Think of them as pre-made toolkits that save you time and effort while ensuring you have the essential building blocks for your microservice.

3. Benefits of Helidon’s Modularity

Helidon’s core philosophy of modularity offers a multitude of advantages for developers building microservices applications in Java. Here’s a breakdown of how this approach empowers you:

4. Building Microservices with Helidon

Helidon’s modularity shines through its ability to build microservices with only the necessary components. Here’s a glimpse into creating a basic web service using Helidon SE, demonstrating this approach in action:

Scenario:

Imagine we need a simple microservice that exposes a single endpoint to return a friendly greeting message.

Modular Approach:

1. Core Library Selection: Since we’re building a web service, we’ll leverage the Helidon SE (Jakarta Servlet API) library. This provides the foundation for handling HTTP requests and responses.
2. Code Structure: Here’s a basic code example showcasing the microservice using Helidon SE:

import javax.enterprise.context.ApplicationScoped;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

import io.helidon.micro.annotations.RegisterWith;
import io.helidon.webserver.Routing;

@ApplicationScoped
@RegisterWith(Routing.builder())
public class GreetingService {

    @GET
    @Path("/greet")
    @Produces(MediaType.TEXT_PLAIN)
    public String greet() {
        return "Hello from Helidon Microservice!";
    }
}

Explanation:

• We define a GreetingService class with a greet method that returns a simple message.
• The @ApplicationScoped annotation indicates the service has application-wide scope.
• The @RegisterWith(Routing.builder()) annotation registers the service with the Helidon web server routing mechanism.
• The @GET, @Path("/greet"), and @Produces annotations define the endpoint details – a GET request to /greet that produces plain text content.

Modular Advantage:

Notice how we only used Helidon SE for this basic web service. If we needed additional functionalities like asynchronous processing, we could have introduced the Helidon Reactive library without affecting the existing code. This modularity allows us to build microservices with only the components they truly require.

Real-world Applications:

Helidon’s modularity extends beyond simple greetings. Imagine building microservices for user authentication, order processing, or product management in an e-commerce application. By choosing the appropriate Helidon libraries for each microservice, you can create a lean and efficient architecture that scales effectively.

This brief example serves as a stepping stone. The complete documentation provides extensive resources and tutorials to delve deeper into building more complex and feature-rich microservices with a modular approach.

5. Conclusion

In this exploration of Helidon, we’ve unveiled a powerful framework for crafting modern microservices applications in Java. The key takeaway? Helidon’s modular approach empowers you to build microservices with freedom and flexibility.

By leveraging a collection of core libraries, you can choose only the functionalities your microservices require. This leads to leaner, more focused applications that are easier to maintain and test. Pre-configured Helidon Stacks accelerate development by providing a foundation for common use cases. Furthermore, Helidon integrates seamlessly with existing Java technologies, allowing you to leverage your current expertise and libraries.

Do you want to know how to develop your skillset to become a Java Rockstar?

Subscribe to our newsletter to start Rocking right now!

To get you started we give you our best selling eBooks for FREE!

1. JPA Mini Book

2. JVM Troubleshooting Guide

3. JUnit Tutorial for Unit Testing

4. Java Annotations Tutorial

5. Java Interview Questions

6. Spring Interview Questions

7. Android UI Design

and many more ....

I agree to the Terms and Privacy Policy

Sign up

Thank you!

We will contact you soon.