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Creating a Messaging App Using Spring for Apache Kafka, Part 1

By Kürşat Kutlu Aydemir
April 8, 2020

Photo by Click and Learn Photography at Unsplash

This article is part of a series. The GitHub repository with code examples can be found here.

Spring is a popular Java application framework. Apache Kafka is a fault-tolerant, fast, and horizontally scalable distributed stream-message broker. Spring for Apache Kafka applies the overall concepts of Spring to Java applications based on Kafka.

Since Kafka can establish a fast and fault-tolerant stream data pipeline it can be used as an orchestrator. In this article I’ll explain how to create a spring-kafka project, add dependencies and use Kafka to create a messaging app.

Initialize Spring project

Spring projects can be built from scratch using Spring Initializr. I like to keep the default options. Most Spring projects use Maven. I set the group id as com.endpoint and the artifact as SpringKafkaMessaging which makes the base package name com.endpoint.SpringKafkaMessaging.

When we are done with the initial project setup we press the “GENERATE” button to download an empty Spring Boot project in a zip file. You can then use your favorite IDE to open and start developing your project. I prefer Eclipse for Java projects. Here’s what it …

Installing Ubuntu 18.04 to a different partition from an existing Ubuntu installation

By Bharathi Ponnusamy
April 6, 2020

Photo by Patryk Grądys on Unsplash

Our Liquid Galaxy systems are running on Ubuntu 14.04 LTS (Trusty). We decided to upgrade them to Ubuntu 18.04 LTS (Bionic) since Ubuntu 14.04 LTS reached its end of life on April 30, 2019.

Upgrading from Ubuntu 14.04 LTS

The recommended way to upgrade from Ubuntu 14.04 LTS is to first upgrade to 16.04 LTS, then to 18.04 LTS, which will continue to receive support until April 2023:

14.04 LTS → 16.04 LTS → 18.04 LTS

Ubuntu has LTS → LTS upgrades, allowing you to skip intermediate non-LTS releases, but we can’t skip intermediate LTS releases; we have to go via 16.04, unless we want to do a fresh install of 18.04 LTS.

For a little more longevity, we decided to do a fresh install of Ubuntu 18.04 LTS. Not only is this release supported into 2023 but it will offer a direct upgrade route to Ubuntu 20.04 LTS when it’s released in April 2020.

Installing Clean Ubuntu 18.04 LTS from Ubuntu 14.04 LTS

Install debootstrap

The debootstrap utility installs a very minimal Debian system. Debootstrap will install a Debian-based OS into a sub-directory. You don’t need an installation CD for this. However, you need to have access to the corresponding Linux …

Magento 2: Creating a custom module

By Juan Pablo Ventoso
April 1, 2020

Photo by Babatunde Olajide, cropped from original

A Magento module is a set of classes and routines that will depend on and interact with other Magento classes in order to add a specific feature to a Magento application. While a theme is orientated towards the front-end and user experience, a module is orientated towards backend logic and application flow.

We will need to create a custom module if we want to add or change the existing logic at a level where Magento doesn’t provide a setting or option for it. For example, if our business has a specific feature or set of features or requirements that are not common to the market, a module can fill that gap for us.

Creating a basic Magento 2 module

Creating a simple module in Magento 2 is not that hard. We will need to accomplish the following tasks:

• Create a new directory for the module
• Create a registration.php script
• Create a etc/module.xml information file
• Install the new module

Creating a new directory for the module

Where should the new directory for our module be placed? We have two options to choose from:

• app/code/{vendor}/
• vendor/{vendor}/

If your module is intended for a specific website you’re working on, you can use …

Salesforce Integration with Node.js

By Dylan Wooters
March 27, 2020

Photo by Dylan Wooters, 2020

Salesforce is huge. It is currently the dominant customer relationship management (CRM) provider, accounting for around 20% of market share. Businesses are using Salesforce not only as a traditional CRM solution, but also for novel purposes. Salesforce can serve as a backend database and admin portal for custom apps, or as a reporting tool that pulls data from various systems.

This growth leads to increasing demand for Salesforce integrations. The term “Salesforce integration” may conjure up images of expensive enterprise software or dense API documentation, but it doesn’t have to be that way. You can work with Salesforce easily using Node.js and the npm package JSforce. An example of a project that might benefit from this kind of Node.js integration is an e-commerce website where order data is loaded to and from Salesforce for order fulfillment, tracking, and reporting.

In this post we’ll cover how to connect to Salesforce using JSforce, the basics of reading and writing data, as well as some advanced topics like working with large amounts of data and streaming data with Socket.IO.

Setting Up

You’ll first want to install Node.js on your local machine, …

An Introduction to webpack 4: Setting Up a Modern, Modular JavaScript Front-End Application

By Kevin Campusano
March 26, 2020

Image taken from webpack.js.org

I’ve got a confession to make: Even though I’ve developed many JavaScript-heavy, client side projects with complex build pipelines, I’ve always been somewhat confused by the engine that drives these pipelines under the hood: webpack.

Up until now, when it came to setting up a build system for front-end development, I always deferred to some framework’s default setup or some recipes discovered after some Googling or StackOverflow-ing. I never really understood webpack at a level where I felt comfortable reading, understanding and modifying a config file.

This “learn enough to be effective” approach has served me well so far and it works great for being able to get something working, while also spending time efficiently. When everything works as it should, that is. This approach starts to fall apart when weird, more obscure issues pop up and you don’t know enough about the underlying system concepts to get a good idea of what could’ve gone wrong. Which can sometimes lead to frustrating Googling sessions accompanied with a healthy dose of trial and error. Ask me how I know…

Well, all that ends today. I’ve decided to go back to basics with …

Web Projects for a Rainy Day

By Elizabeth Garrett Christensen
March 25, 2020

Image by Yellowstone NPS on Flickr

With the COVID-19 quarantine disrupting life for many of us, I thought I’d put together a list of things you can do with your website on a rainy day. These are things to keep your business moving even if you’re at home and some of your projects are stuck waiting on things to reopen. If you’re looking for some useful things to do to fill your days over the next few months, this post is for you!

Major Version Updates

Make a list of your entire stack, from OS to database to development frameworks. Note the current version and research the current supported versions. I find Wikipedia pages to be fairly reliable for this (e.g. en.wikipedia.org/wiki/CentOS). Ok, so what things need to be updated, or will need to be in the next year? Start on those now and use some downtime to get ahead of your updates.

Sample of a client’s stack review

What is SharePoint?

By Dan Briones
March 25, 2020

Image by Taylor Vick

People often ask me about SharePoint, Microsoft’s browser-based collaboration platform which allows users to upload and share all kinds of documents, images, messages, and more. The product has nearly two decades of history and there are still many who don’t know much about it.

The SharePoint platform has grown over those years, but its capabilities have expanded in such a way that it can be quickly dismissed from consideration out of fear of the complexity of its implementation and the cost of deployment. These fears may be unfounded, however. Especially if you are already on Office 365, SharePoint may be included in your plan.

SharePoint was designed as a framework to create and share content on the web without the need to write code. Its purpose was to allow everyone in the organization to collaborate without any specific programming skills. This framework grew over time, adding many different types of content allowing for interactions with other frameworks increasing the effectiveness of any organization’s work product or intellectual property and communications.

Flavors of SharePoint

There are two ‘flavors’ of SharePoint. You can use Microsoft’s …

Serialization and Deserialization Issues in Spring REST

By Kürşat Kutlu Aydemir
March 17, 2020

Photo by Annie Spratt

Spring Boot projects primarily use the JSON library Jackson to serialize and deserialize objects. It is especially useful that Jackson automatically serializes objects returned from REST APIs and deserializes complex type parameters like @RequestBody.

In a Spring Boot project the automatically registered MappingJackson2HttpMessageConverter is usually enough and makes JSON conversions simple, but this may have some issues which need custom configuration. Let’s go over a few good practices for them.

Configuring a Custom Jackson ObjectMapper

In Spring REST projects a custom implementation of MappingJackson2HttpMessageConverter helps to create the custom ObjectMapper, as seen below. Whatever custom implementation you need to add to the custom ObjectMapper can be handled by this custom converter:

public class CustomHttpMessageConverter extends MappingJackson2HttpMessageConverter {

    private ObjectMapper initCustomObjectMapper() {
        ObjectMapper customObjectMapper = new ObjectMapper();
        return customObjectMapper;
    }

    // ...
}

Additionally, some MappingJackson2HttpMessageConverter methods, such as writeInternal, can be useful to override in …