Microservices architecture has gained significant popularity as it provides a scalable and modular approach to building software applications. In the Java ecosystem, GlassFish and Eclipse MicroProfile offer a powerful combination to build robust and efficient microservices. In this blog post, we will explore how to build Java microservices using GlassFish and Eclipse MicroProfile.

Setting Up the Environment

To get started, make sure you have the following tools installed on your machine:

• Java Development Kit (JDK): Ensure that you have JDK 8 or above installed.
• GlassFish Server: Download and install the latest version of GlassFish from the official website.
• Eclipse IDE: Install the Eclipse IDE for Java EE Developers, as it comes with built-in support for GlassFish and MicroProfile.

Creating a Microservice Project

1. Open Eclipse IDE and navigate to File -> New -> Project.
2. Select MicroProfile under the Java EE category and click Next.
3. Enter a Project Name for your microservice project and choose a Target Runtime as GlassFish.
4. Click Finish to create the project.

Implementing Microservices

Now, let’s create a simple microservice endpoint using the Eclipse MicroProfile API.

package com.example.microservices;

import org.eclipse.microprofile.config.inject.ConfigProperty;
import org.eclipse.microprofile.openapi.annotations.Operation;
import org.eclipse.microprofile.openapi.annotations.tags.Tag;
import org.eclipse.microprofile.rest.client.inject.RestClient;

import javax.inject.Inject;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

@Path("/hello")
@Tag(name = "Hello Microservice")
public class HelloMicroservice {

    @Inject
    @ConfigProperty(name = "greeting.message")
    private String greetingMessage;

    @GET
    @Path("/")
    @Produces(MediaType.TEXT_PLAIN)
    @Operation(summary = "Get a personalized greeting")
    public String getGreeting() {
        return greetingMessage;
    }
}

In the above code, we create a simple RESTful endpoint using the @GET annotation. The @ConfigProperty annotation is used to inject the greeting.message property from the configuration file. The @Operation and @Tag annotations are used for OpenAPI documentation.

Deploying the Microservice

To deploy the microservice to GlassFish, follow these steps:

1. Right-click on the project in Eclipse and select Run As -> Run on Server.
2. Choose the GlassFish server and click Finish.
3. Wait for the server to start and deploy the microservice.

Testing the Microservice

Once the microservice is deployed, you can test it using tools like Postman or by accessing the endpoint URL directly in a web browser.

For example, if GlassFish is running on http://localhost:8080, you can access the microservice endpoint at http://localhost:8080/<context-root>/hello where <context-root> is the name of your microservice project.

Conclusion

Building Java microservices with GlassFish and Eclipse MicroProfile provides a flexible and efficient way to develop scalable applications. With the powerful features offered by MicroProfile, developers can focus on building modular and loosely coupled microservices. By following the steps mentioned in this blog post, you can start building your own Java microservices using GlassFish and Eclipse MicroProfile.

#Java #Microservices #GlassFish #EclipseMicroProfile