Using Apache POI With Protected Excel Files

Jonny Hackett Articles, Development Technologies & Tools, Java, Spring Batch 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 Articles, AWS, Cloud, Development Technologies & Tools, Java 1 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 Articles, Development Technologies & Tools, JavaScript, Mobile, React, React Native 1 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.

Java Development Using Visual Studio Code

Todd Horn Articles, Design, Java, Programming, Project Management Leave a Comment

Over the last few years, I have worked on several .NET and JavaScript projects. My go-to IDE for Angular, Node, and (in starting to learn) React has been Visual Studio Code, along with Visual Studio Enterprise for C#.

Recently, I started on a new team and project that was in Java. Our initial thought was to switch back over to Spring Tool Suite or IntelliJ. But, there are some really good extensions now for Java in VS Code that made that transition unnecessary. So we decided to take a look at what Visual Studio code could do for us – we were very pleasantly surprised!

In this post, I provide links and information to get you started down the right path for Java in Visual Studio Code.

JavaScript Bake-Off: Angular, React, and Vue

David Pitt Angular, Articles, JavaScript, Opinion, React, Single-Page Application, Vue.js Leave a Comment

As Keyhole consultants, we are exposed to a plethora of technology stacks and implementations from client project to client project. Particularly with our enterprise clients, great care must go into selecting the best technologies for the company’s technical needs and current landscape. After all, they don’t want to be re-writing the same application in just a couple of years due to lackluster choices and shortage of developers to add functionality.

In this post, we present an open source reference application developed three times using three different frameworks, React, Vue & Angular.