Microservices in Java Explained

Microservices are popular in the technology world but do you know there are still many people who don’t know what they are and how they work. Before we can get into the details of how to write microservices in Java, we need to define what microservices are first and go over some basics about them. Then we’ll move on to talking about how to write microservices in Java, both from a conceptual standpoint and from a programming language standpoint.

Running applications as microservices has taken over the enterprise world, with some data claiming as many as 90% of companies run their applications this way now.

Microservices are basically used for developing a larger, more complex application that is developed as a combination of smaller services.

This guide will walk you through the basics of what microservices in JAVA are, why they’re useful, and how you can use them in your Java applications to improve your application architecture and overall code quality.

By the end of this article, you’ll have a clear understanding of how you can use microservices in your own Java applications and how to improve your Java coding skills overall. So let’s get started!!

What is Microservices Architecture?

Microservices are an architectural style or design pattern.It is a software design paradigm that develops a single application as a suite of small services, each service running in its own process and communicating with a lightweight mechanism.

Microservices, also known as services-oriented architecture (SOA), This allows for fast deployment, scaling, and changing of each individual service independently.

The main principles behind microservices include independent teams, continuous delivery, and autonomous deployment.

Microservices in JAVA are loosely coupled, meaning that they can be developed by different developers and on different timelines.

Microservices greatly improve modularity. Each microservice has its own purpose and handles only one concern, which allows you to modify them without affecting other parts of your system.

Also, they are more resilient when problems occur because it’s easier to deploy new code when needed rather than replacing several modules at once.

What are the Benefits of Microservices?

Microservice architecture also provides lots of benefits. How they allow your developer to write code.

• NewTechnology and Process Adaption: Microservices architecture is enabled to adapt new technology and process very easily.

• Small and focused: This means they can be built and deployed much faster than monolithic applications. As small applications with limited dependencies, microservices lend themselves well to containerization as well.

• But speed isn’t everything: another advantage is their granularity.

• Loosely Coupled: This feature enables deployment rapidly and frequently.

• Dynamic Scaling: If Microservice are cloud enabled they can scale dynamically and you procure hardware and release it dynamically. Because you are developing small components.

Examples of Microservices Frameworks for Java

You can use various microservice frameworks for developing java. Spring Cloud, Dropwizard, Vert.x, Ratpack, Wildfly Swarm, etc. Microservices frameworks provide easy-to-use APIs and SDKs for building microservices using one of these technologies.

Frameworks also provide ways to handle service discovery, load balancing, and fault tolerance. Spring boot is to work on top of language for inversion of control, aspect-oriented programming, and others.

Examples of such frameworks include Spring Cloud (based on Spring Boot), Dropwizard (from Pivotal), Vert. x (from Red Hat), and Ratpack (from Netflix). Newer frameworks such as Wildfly Swarm bring together multiple JVM languages including Java, Groovy, and Clojure with minimum boilerplate code or no coding at all!

How to Create Using Dropwizard

This is a tutorial on how to use Dropwizard, an open-source framework for developing microservices. Microservices are small application components that can be independently developed and released.

The Dropwizard framework helps you build microservices in Java. It comes with libraries of code called 'Gears' that help you quickly set up common functionality like health checks, user authentication, and data persistence.

It has built-in support for Amazon's AWS Lambda service, making it easy to run your code as part of a serverless cloud application.

In short, if you're new to microservices development and want to try it out using a supported platform (and love JVM languages), give Dropwizard a shot!

With mevan you can setup Dropwizard application.

With the help of the latest version of DropWizard, you add in a dropwizard.version property in your POM.

<properties>

<dropwizard.version>LATEST VERSION</dropwizard.version>

</properties>

Then list the dropwizard-core library:

<dependencies>

<dependency>

<groupId>io.dropwizard</groupId>

<artifactId>dropwizard-core</artifactId>

<version>${version}</version>

</dependency>

</dependencies>

You can also create an application class, configuration class, a resource class and health check.

Using Spring Boot for Microservices

Microservices is a software design pattern and architectural approach that aims to build a system out of small, independent modules (the micro-services) each running in its own process and communicating with lightweight mechanisms, often an HTTP resource API. Using fully automated deployment machinery, each service is based on business capabilities and can be independently deployed. Most of today's applications are monolithic: they provide one-stop shopping but they may be hard to extend and reuse due to their complex interdependence. Microservices allow us to solve problems by composing robust services, instead of building monolithic software systems where everything is deeply coupled together.

Microservices with spring is the perfect example. It resolves the major challenges of microservices. Spring boot embedded servers which are easy to deploy with the containers help in monitoring the multiple components and facilitate in configuring the components externally and all challenges are completely resolved with the help of spring boot.

Now let’s discuss some exciting Spring Boot Projects for microservices.

• Building Web apps and web services

• Using for connecting API’s from social media

• For Authentication and security purposes

• Data access, messaging, transaction management, dependency injection, and web apps.

Let’s Discuss Some Frameworks

Jersey

Jersey is a lightweight, open source, portable, pure java framework that is used to create RESTful services discovery and clients. Jersey enables developers to implement their microservices based applications with ease. You can easily build your microservices applications by taking advantage of Jersey and other java frameworks. The jar file of the jersey should be present on classpath during developing your web application.

Play Framework

Play Framework is a web application framework that comes with support for microservices. It is designed to be faster and easier to use than other frameworks like Java EE or Ruby on Rails. Thanks to its ecosystem of frameworks, Play is suitable for building applications across many different languages and platforms. For instance, an Android app written in Java can use Play to handle data sync and server communication.

The Best Practices for Microservices

Before you start building, it’s important to understand what a microservices architecture entails and why it makes sense for your business. Designing, developing, and operating microservices is different from building a monolithic application—and there are specific things you should consider before starting. To that end, let’s walk through what microservices are and how they differ from traditional application design. From there we can move on to examining how to build a new set of services for your company using Spring Boot and Spring Cloud Services, two libraries that make building microservices easier by providing opinionated tooling across cloud environments. Finally, we’ll step through some best practices for deploying microservices once they’re up and running.