Tutorials

Creating a JavaFX World Clock from Scratch (Part 6)

Hello, and welcome to the last part of this series of articles on creating a JavaFX World Clock from scratch!

In this part, I will show you how to make WebService calls (RESTful) to retrieve weather data based on geographic locations.

If you remember, in Part 5 you learned how to use the JavaFX WebView and the popular mapping library Leaflet JS enabling the user to discover geographic locations. In Part 6, I will show you how I used Java 11’s Http Client to retrieve and display weather content. If you are new to this series, you can visit Part 1-5.

Debugging Java on the Command Line

Some bugs are hard to replicate on your personal computer but easily replicated on production or test machines. It is a common situation that professional Java developers deal with frequently. To debug such problems, OpenJDK provides two tools, remote debugging and jdb.

This article focuses on jdb.

For Java applications, typical production and test machines are Linux servers without display managers, so that only command line tools are available. Here we cannot use professional IDEs like IntelliJ IDEA, Eclipse, or Apache NetBeans IDE.

In such scenarios, we can use jdb. jdb is a command line debugger and it is part of the OpenJDK.

Jakarta EE Application Deployment to Kubernetes Cluster in Jelastic PaaS

Recently, Jelastic were asked to sponsor cloud hosting of a Jakarta EE project, called Cargo Tracker.

Being a member of Jakarta EE Working Group, Jelastic wanted to support the community and thus we started to run this application at one of our service providers (Scaleforce).

In this article, we would like to show how to deploy the Jakarta EE projects to the Kubernetes cluster within Jelastic PaaS using Cargo Tracker as an example.

Creating a Simple Spring Boot Application in IntelliJ IDEA

In this tutorial, we’ll use the New Project Wizard in IntelliJ IDEA to create a Spring Boot project with the Spring Web dependency.

We’ll also create a Spring Controller and served some text to the local Tomcat webserver.

Finally, we’ll add a test for our HTTP call.

Automatic WildFly Clustering in Managed Domain Mode and Scaling inside Containers

How to extend WildFly from standalone server to cluster in managed domain mode inside containers for running cloud-native scalable applications?

There is no need to rebuild the whole application architecture in order to gain the required outcome from both managed domain mode and container technology.

Migration of legacy projects from VMs to micro clusters with system containers is not that painful at all.

It brings a “rich taste” of flexibility and efficiency for increasing competitive advantage.

Modern JavaFX Game Development with FXGL: Pong (Simple)

In this tutorial we will make a very simple clone of the classic Pong game using the FXGL game engine.

We will be using the latest (currently 11.15) version of FXGL via Maven or Gradle.

The full source code is available at the end of this page.

Jenkins Cluster for Continuous Integration and Delivery (CI/CD) inside Jelastic PaaS

In this article, we’ll describe how to install Jenkins cluster with slave nodes auto-discovering and self-registering inside a master node.

Jelastic PaaS implemented this solution in Jenkins DevOps Pack that can be installed from the Marketplace or through environment setup wizard as a New Environment.

In this tutorial we’ll cover both. Also, you will find out how to build a simple Java project hosted on GitHub using Jelastic Maven plugin.

OIDC Client with Mutual TLS Client Authentication

Learn how to set up an OpenID Connect (OIDC) client with Spring Security using mutual TLS as a method for authenticating the client.

Mutual TLS is not supported out-of-the-box by Spring Security, so there are a few steps that need to be completed to use this feature.

In order to make the example code a bit more tangible, we will be using the Curity Identity Server as the Authorization Server, but you can use any Authorization Server.

Git Archeology

Most people will start with using “git blame” (or the respective functionality within their IDE/editor).

But on most non-trivial projects, you usually end up with a refactoring commit, a rename, or a trivial cross-project fix like switching to another assertion library. At first glance, we only see the most recent changes, not the most important ones.

We need to carefully remove layer by layer of sand and dirt that has been swept over the real changes to unearth them.

Device Monitoring with JavaFX and FXGL

In a previous post, Getting Started with FXGL Game Development, we already have taken a look at the FXGL game development framework developed by Almas Baimagambetov.

But, this game engine can also be used for other use cases. In this post, we will be building a system monitoring dashboard, which can run on a Raspberry Pi.

The dashboard can be used to keep an eye on any device that can report its state to a queue. And, for me personally, it finally solves the problem of finding the IP addresses of all my Raspberry Pi’s when my router decided to shuffle them.

How To Bring Your Java Microservices To The Cloud

All companies are software companies, and businesses will always experience the challenge of keeping integrations between users and applications scalable, productive, fast, and of high quality.

To combat this, cloud, microservices, and other modern solutions come up more and more in architectural decisions.

Here is the question: Is Java prepared to deal with these diverse concepts in a corporate environment?