In today’s world of software development, microservices architecture has gained significant popularity due to its ability to create scalable and resilient applications. Microservices are small, loosely coupled services that work together to provide the functionality of a larger application. In this blog post, we will explore how to build microservices using GlassFish and Java.

What is GlassFish?

GlassFish is an open-source Java EE application server that provides a runtime environment for Java-based applications. It offers robust support for building and deploying enterprise-level applications, including microservices.

Step 1: Setting up GlassFish

First, we need to download and install GlassFish on our development machine. Visit the official GlassFish website (https://glassfish.org) and download the latest version. Once downloaded, follow the installation instructions for your operating system.

Step 2: Creating a Java microservice

Now that GlassFish is installed, let’s create our first Java microservice. Open your favorite integrated development environment (IDE) and start a new Java project. Create a new class file, for example, HelloService.java, and type the following code:

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;

@Path("/hello")
public class HelloService {

    @GET
    @Produces("text/plain")
    public String sayHello() {
        return "Hello, world!";
    }
}

The above code defines a basic RESTful microservice that handles HTTP GET requests at the /hello endpoint and returns a plain text response of “Hello, world!”.

Step 3: Deploying the microservice to GlassFish

To deploy our microservice to GlassFish, we need to package it as a WAR (Web Application Archive) file. In your IDE, generate the WAR file for your project.

Next, start the GlassFish server by running the following command in your command prompt or terminal:

$ <glassfish-installation-directory>/bin/asadmin start-domain

Once the server is running, deploy the microservice by executing the following command:

$ <glassfish-installation-directory>/bin/asadmin deploy <path-to-war-file>

The <path-to-war-file> should be replaced with the actual path to your generated WAR file.

Step 4: Testing the microservice

Once the microservice is deployed, we can test it by accessing the following URL in a web browser or using an API testing tool:

http://localhost:8080/<your-war-file-name>/hello

If everything is set up correctly, you should see the response “Hello, world!” displayed on the screen.

Conclusion

Building microservices using GlassFish and Java provides a powerful and flexible way to develop scalable applications. With the ability to leverage Java EE features and the robustness of GlassFish, developers can create robust and efficient microservices. Start exploring the world of microservices with GlassFish today!

#java #microservices