In today’s world of cloud-native applications, developing microservices using Java has become more popular than ever. Microservices offer a modular and scalable architectural approach to building software systems. In this article, we will explore how to develop Java microservices using GlassFish as the application server and Eclipse MicroProfile Config for configuration management.

GlassFish Application Server

GlassFish is a lightweight and open-source Java EE application server that provides a robust runtime environment for deploying and running Java applications. It offers support for the latest Java EE specifications and is known for its ease of use and simplicity. To get started, you can download GlassFish from the official website.

Eclipse MicroProfile Config

Eclipse MicroProfile Config is a specification that provides a simple and flexible way to handle configuration in microservices. It allows developers to externalize configuration values from their code, making it easier to manage and update settings without the need for redeployment.

To use Eclipse MicroProfile Config, we need to add the appropriate dependencies to our project. In Maven, you can include the following dependencies in your pom.xml file:

<dependency>
    <groupId>org.eclipse.microprofile.config</groupId>
    <artifactId>microprofile-config-api</artifactId>
    <version>2.0</version>
</dependency>
<dependency>
    <groupId>org.eclipse.microprofile.config</groupId>
    <artifactId>microprofile-config-tck</artifactId>
    <version>2.0</version>
    <scope>test</scope>
</dependency>

Using Eclipse MicroProfile Config in GlassFish

Once we have GlassFish and the MicroProfile dependencies set up, we can start utilizing the MicroProfile Config in our Java microservices. The first step is to create a configuration file, commonly named microprofile-config.properties, that will contain the key-value pairs for our configuration settings.

Here’s an example of a microprofile-config.properties file:

# Database Configuration
db.url=jdbc:mysql://localhost:3306/mydatabase
db.username=admin
db.password=secret

# Email Configuration
email.host=smtp.gmail.com
email.port=587
email.username=myemail@gmail.com
email.password=mypassword

Next, in our Java code, we can access these configuration values using the ConfigProvider API provided by Eclipse MicroProfile Config.

import org.eclipse.microprofile.config.Config;
import org.eclipse.microprofile.config.ConfigProvider;

public class MyMicroservice {
    
    public static void main(String[] args) {
        Config config = ConfigProvider.getConfig();
        
        String dbUrl = config.getValue("db.url", String.class);
        String dbUsername = config.getValue("db.username", String.class);
        String dbPassword = config.getValue("db.password", String.class);
        
        // Use the configuration values in your microservice logic
        // ...
    }
}

By following these steps, we can easily manage and access configuration values in our Java microservices using GlassFish and Eclipse MicroProfile Config. This allows for greater flexibility and agility in managing and updating our application’s settings.

Developing Java microservices has never been easier, thanks to tools like GlassFish and specifications like Eclipse MicroProfile Config. With a simple configuration file and a few lines of code, we can unleash the power of microservices and build scalable and modular applications.

#Java #Microservices