In today’s fast-paced world, building reactive microservices has become a crucial aspect of modern application development. Reactive microservices enable developers to design scalable and resilient systems that can handle a large number of concurrent requests while maintaining low response times. In this blog post, we will explore how GlassFish and Eclipse MicroProfile Reactive Streams Operators can be used together to create reactive microservices in Java.

GlassFish: The Java EE Application Server

GlassFish is an open-source Java EE application server that provides a runtime environment for Java EE applications. It offers a wide range of features and APIs for building enterprise-grade applications, including support for web services, messaging, security, and more. GlassFish comes with an embedded Apache Kafka broker, which makes it an excellent choice for building reactive microservices.

Eclipse MicroProfile Reactive Streams Operators

Eclipse MicroProfile Reactive Streams Operators is a specification that defines a set of APIs and operators for building reactive applications in Java. It builds on top of the Reactive Streams specification, which provides a standard for asynchronous stream processing in Java. MicroProfile Reactive Streams Operators extends the core Reactive Streams interfaces to provide additional operators, such as filter, map, flatMap, and more.

Let’s take a closer look at how GlassFish and MicroProfile Reactive Streams Operators can be utilized together to build reactive microservices.

Setting Up GlassFish with Reactive Streams Operators

To get started, you will need to have GlassFish installed on your system. You can download the latest version of GlassFish from the official website and follow the installation instructions.

Once GlassFish is installed, you can add the MicroProfile Reactive Streams Operators dependency to your project. Include the following dependency in your project’s pom.xml file:

<dependency>
    <groupId>org.eclipse.microprofile.reactive-streams-operators</groupId>
    <artifactId>microprofile-reactive-streams-operators</artifactId>
    <version>1.0</version>
    <scope>provided</scope>
</dependency>

Creating Reactive Microservices with GlassFish and Reactive Streams Operators

To create a reactive microservice, you can start by defining a JAX-RS resource class annotated with the @Path annotation to specify the URL path for the microservice. Next, you can create a method and annotate it with the @GET or @POST annotation to handle incoming HTTP requests.

Inside the method, you can use the MicroProfile Reactive Streams Operators to process the incoming data asynchronously. Here is an example of how you can use the map operator to transform the incoming data:

@GET
@Path("/transform")
public CompletionStage<String> transformData() {
    return ReactiveStreams.of("Hello", "World")
        .map(String::toUpperCase)
        .toList()
        .run();
}

In this example, the ReactiveStreams.of method is used to create a stream of strings. The map operator is then used to transform each string to uppercase. Finally, the toList operator collects all the transformed strings into a single list, which is returned as a CompletionStage.

Conclusion

Building reactive microservices with GlassFish and Eclipse MicroProfile Reactive Streams Operators provides a powerful combination for creating scalable and resilient applications. GlassFish’s support for Java EE and embedded Kafka makes it an excellent choice for running reactive microservices. The MicroProfile Reactive Streams Operators specification offers a rich set of APIs and operators for processing asynchronous streams of data.

By leveraging the capabilities of GlassFish and MicroProfile Reactive Streams Operators, developers can build highly responsive and efficient microservices that can handle a large number of concurrent requests with ease.

#reactiveprogramming #microservices