Archive: October 2020

Game Development in Java

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Johan Kragt

In my early days as a software developer I worked at a small game studio. This was back in the days when ActionScript and Flash were still a thing.

At JCore during Corona times we’ve spent part of the JCore Fast Track looking at game development in Unity3D and the Unreal engine. These engines work on C#/JavaScript and C++ respectively.

Nowadays the language I’m most comfortable with is Java. A little while ago I was wondering whether it would be possible to create a game in Java.

Of course almost all languages support some sort of drawing, so technically the answer would be a straight yes. Modern engines and libraries offer support for OpenGL rendering and provide a lot of tools out of the box.

Though there are 3D engines for Java I’ll be focusing on a 2D game, mostly because the complexity of 3D and its assets makes creating anything resembling a 3D game a daunting task.

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Implementing a https enabled redirect service using Firebase

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Rob Brinkman

More and more web-traffic is moving to https instead of http protocol. Because users are using a modern browser that defaults to https or a browser extension like Https-By-Default . A great development from a security- and privacy perspective. But with some side effects as it pointed out that the redirect service offered by our hosting provider does not fully support https which causes a security warning.

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Introduction to OData

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Justus Brugman

As developer, you probably have to work with APIs. Either you consume them, or perhaps you build them. Most of the time an API provides some sort of JSON response or perhaps XML. When the implementation is complete, it provides documentation as well, using the OpenAPI specification. This however is not what this blog is about.

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Automating hosting RevealJS slides on GitLab

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Deniz Turan

RevealJS is an awesome tool made with JavaScript, which allows you create slides for a presentation using HTML or if you use a plugin, Markdown. The great thing about that is, that you could have your slides in git, with proper version control. To run your slides, all you need is a web server which serves static content, for example you could do this locally using Python’s SimpleHttpServer. That’s where GitLab comes in, with GitLab pages you can host any static web content you want, so that’s what I will show in this blog, automatically hosting your RevealJS slides on GitLab with every commit of your slides.

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Spring WebFlux : reactor meltdown - slow responses

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Michel Breevoort

WebFlux is the reactive web framework for Spring. The programming model is easy but using it could be cumbersome if you don’t know the consequences when used incorrectly. This post will show what the consequences are when the reactive-stack is not used correctly. It will answer the question: why is my (health) endpoint sometimes so slow?

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Why passwords are done wrong

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Kees Nederkoorn

Password must be at least 12 characters long, must include lower and upper case letters, must include numbers, must include special characters, must have at least 3 numbers, must have at least 2 special characters, may not include words in the dictionary. Your password is rejected because it does not comply to our policy. A policy that isn’t published anywhere, but you must make one that complies anyway. Your password has expired, make a new one that does not resemble any of the passwords that you have created in the past. And it’s all useless. We’re all doing it wrong.

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Using AWS API Gateway as an proxy

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Thomas de Groot

During my last year at JCore I was given the opportunity to do deep-dive in a self-chosen topic in the form of a 'Specialisation'. For this 1-year project I chose to dive deep into AWS how it works and how I, as a developer, make use of it. Some of the topics I covered during this were: DevOps, CI/CD and Security. As a demo and as use case I created a simple pubquiz application in which you can register and have a custom form for your answers. During the development of this application I faced different challenges that I had to overcome. This blog is about how I created a simple API that is exposed to the internet and how I tried to tackle the challenges of security, scalability and adaptability.

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Clojure Goodness: Formatting With Java Format String

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Hubert Klein Ikkink

In Clojure we can format a string using Common Lisp format syntax or the Java format string syntax. In the post we will look at the how we can use the Java format string syntax. We must use the format function in the clojure.core namespace. The method delegates to the standard JDK String#format method. The first argument is a format string followed by one or more arguments that are used in the format string. We can look up the syntax of the format string in the Javadoc for the java.util.Formatter class.

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Git: rebase vs. merge

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Kees Nederkoorn

We have all gotten acquainted with git in the last decade. We have adopted a way of working that has made it easy for all of us to work together in large teams and reduced the times our code changes collided to a minimum. When we do run into problems, they’ve culminated to a single important moment; the merge. We all know the merging feature of git with all its pro’s and con’s. But what about another feature of git: rebase?

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