Creating A Blockchain In JavaScript

Vince Pendergrass Blockchain, JavaScript, Technology Snapshot Leave a Comment

Blockchain is all the buzz now. And for good reason! A distributed public ledger that is extremely secure through encryption?! Imagine the millions of applicable use cases. A blockchain can be created and maintained using any modern language.

For the purpose of this blog, let’s dive into a blockchain written in JavaScript. Hopefully, this doesn’t just serve as a simple code example but also gives a very basic understanding of how a blockchain actually works.

Do keep in mind this will be very simplist…

Running Your Life With Emacs

Garrett Hopper Problem Solving, Programming, Technology Snapshot Leave a Comment

I program a lot, but I also do a lot of other things using a computer.

The problem is, I often want to use the same efficient key bindings I use while programming when I’m doing other tasks. I want to be writing an email or documentation and edit a code snippet in the same way I normally edit code. I want to manage Git repositories right from my editor without having to touch the mouse. I want to browse the web in my editor, so I can easily copy code examples and run them. I want to track my to-do lists and the amount of time spent on each task.

Imagine if there was a tool that could do all that and a ton more in an efficiently consistent way. That tool is Emacs…

Using Apache POI With Protected Excel Files

Jonny Hackett Java, Problem Solving, Spring Batch, Technology Snapshot 1 Comment

While working on a recent project at a client, we had the opportunity to refactor some data extracts that were using a commercial Excel writing library, which we then converted to using the Apache POI Library for Excel. These data extracts were reports that included some calculated values, and depending on the client, were required to be password protected. When completed, the reports would be emailed to the recipients configured for each client.

In this post, we discuss the challenge of delivering protected Microsoft documents via email. We introduce a Java code solution for emailing password-protected Excel files when using the Apache POI Library.

Some of the required calculations we chose to implement using Excel formulas. Implementing formulas wasn’t a hard task and worked for what was needed.

AWS SNS Push Notifications

Matt McCandless AWS, Cloud, Java, Problem Solving, Technology Snapshot Leave a Comment

Have you ever received endless notifications from the latest application you just downloaded? For example, a bank application that tells you your balance is less than $50. It is likely a message sent directly to your phone through Apple Push Notification Service, Firebase Cloud Messaging, or some other like service.

While you can use any of these services directly, there is a lot to gain by using something like AWS SNS to manage, send, and organize your notifications.

In this post, we show an example of the Push Notification feature of Amazon Simple Notification Service (SNS) using Firebase to handle the iOS and Android messages. Code examples are in Java using Eclipse.

Do note that this blog is solely focused on Push Notification feature of SNS. Keep in mind that SNS can be used for email and SMS messaging, but for brevity, we will steer clear of those.

React Native With Expo

Lou Mauget JavaScript, Mobile, React, Technology Snapshot Leave a Comment

The React Native framework supports an installable mobile application created from JavaScript source code. It is not a React-based web app wrapper. It isn’t a code generator. There is no required application source code in Java, Objective-C, Swift, or Kotlin. Moreover, a single React Native application targets both iOS and Android devices.

In this blog, we show a quick-start that results in an executing application on a phone, within five minutes. That application is live-reloadable, native cross-platform, and written in JavaScript. It is not a web application.