Use Cases on foojay.io - Friends Of OpenJDK

Jakarta Faces, Java Web Framework, Stateless Edition: Marketplace AliFaces

Sat, 29 Aug 2026 19:22:52 +0000

A Fully Stateless Jakarta Faces Marketplace with Server-Side Rendering — No HttpSession, No Saved ViewState, No Sticky Sessions

(see the poc on: AliFaces POC Run On Oracle OCI(Nanos Unikernel))

Jakarta Faces still carries a few persistent assumptions: it is stateful, it requires HttpSession, it needs sticky sessions to scale horizontally, and its server-side rendering model belongs to an older generation of web applications.

AliFaces challenges those assumptions with running code — not a Hello World, but a marketplace-style application with catalog, search, filters, cart, checkout, orders, browsing history, themes, responsive layouts and a JSON API for mobile clients.

Introducing BoxLang AI Explorer: A Local Catalog for Every AI Pattern

Tue, 18 Aug 2026 14:15:48 +0000

Learning a new AI API usually means jumping between scattered documentation pages, guessing at imports, and copy-pasting code that may or may not still work. We wanted something better for BoxLang AI, so we built the BoxLang AI Explorer : a local, browser-based catalog of runnable BoxLang AI examples, organized by category and difficulty, each with guidance, source code, and sample output. You can also try it online at https://ai.boxlang.io/explorer/

Seasons time-lapse - the video

Tue, 09 Jun 2026 12:45:51 +0000

In the first post of this series, I focused on the project foundations: what should I do to create a video from photos taken from the same position year after year? I dedicated the second part to aligning images. It wasn’t as easy as I expected. I stumbled upon new concepts, such as and .

In this third and final post, I want to tackle the video creation itself, explain some “artistic” decisions, and leave the door open to future work.

JC-AI Newsletter #13

Thu, 05 Feb 2026 21:12:12 +0000

Two weeks have passed, and it is time to present a new collection of readings that may shape developments, utilization or ideas in the field of artificial intelligence in 2026.

While significant activity characterizes the AI field, many unresolved research, design, and implementation challenges continue to impact progress. Future advancement depends heavily on understanding the nature of these challenges to approach probabilistic problems from the appropriate directions. This JC-AI newsletter features insightful interviews with key figures in the field, enabling readers to ask the right questions and compare visions of an ‘uncertain future’ against current capabilities to maintain a grounded perspective.

From a JAR to a full-fledged MacOS app

Thu, 05 Feb 2026 10:15:05 +0000

A couple of years ago, I developed a small Kotlin GUI to help me rename my files in batch. I actually created it with different JVM frameworks to compare their relative merits. In any case, I didn’t use it up until last week. And then, I was surprised to see that it didn’t work to rename a network volume, although it had in the past. In this brief post, I aim to describe the issue and its solution.

Bootstrapping a Java File System

Thu, 29 Jan 2026 01:44:32 +0000

So what does file system mean to you? Most think of file systems as directories and files accessed via your computer: local disk, remotely shared via NFS or SMB, thumb drives, something else. Sufficient for those who require basic file access, nothing more nothing less.

That perspective of file systems is too limited: VCS repositories, archive files (zip/jar), remote systems can be viewed as file systems, potentially accessed via the same APIs used to for local file access while still maintaining security and data requirements. Or how about a file system which automatically transcodes videos to different formats or extracts audio metadata for vector searches? Wouldn’t it be cool to use standard APIs rather than create something customized? Definitely!

DocBox v5 - Reborn: Modern API Docs for BoxLang & CFML

Tue, 27 Jan 2026 12:15:45 +0000

Welcome to DocBox v5! We didn’t just update DocBox. We rebuilt it from the ground up.

DocBox v5.0.0 represents a complete architectural rewrite—modern syntax, blazing performance, and a stunning new look that finally brings API documentation into 2025. Gone are the clunky HTML pages of yesteryear. Say hello to a gorgeous, theme-driven single-page application that makes browsing your API docs feel like using a premium developer tool. We have also released a dedicated module for BoxLang: BX-DOCBOX. A fully interactive CLI tool for generating your docs from the command line using pure BoxLang.

BoxLang AI v2: Enterprise AI Development Without the Complexity

Thu, 22 Jan 2026 15:09:25 +0000

One Year. 100+ Features. Unlimited Possibilities.

Just one year ago, in March 2024, we launched BoxLang AI 1.0. Today, we’re thrilled to announce BoxLang AI v2—a massive leap forward that positions BoxLang as one of the most powerful and versatile AI framework on the JVM. This release is 9-months in the making, with over 100 new features! This would have not been possible without all the new features that the BoxLang JVM language exposes to developers like: Server Side Events, HTTP Streaming, HTTP pooling, Caching, and so much more.

Announcing bx-ldap: Enterprise LDAP for BoxLang

Tue, 16 Dec 2025 17:01:13 +0000

We’re excited to announce the release of bx-ldap, a comprehensive LDAP module that brings enterprise-grade directory access to BoxLang! This module goes above and beyond traditional CFML LDAP implementations, offering modern features like connection pooling, event-driven programming, multiple return formats, and a clean, intuitive API.

Note: bx-ldap is a premium module available exclusively to BoxLang +/++ subscribers.

🎯 Why?

Whether you’re integrating with Active Directory, OpenLDAP, or any LDAP-compliant directory service, bx-ldap makes it simple and powerful. From basic queries to complex directory operations, this module handles it all with grace and performance.

BoxLang RSS: Full-Featured RSS/Atom Feed Module for BoxLang

Tue, 02 Dec 2025 11:19:11 +0000

We’re thrilled to announce the release of bx-rss, a comprehensive RSS and Atom feed module that brings powerful syndication capabilities to BoxLang! Whether you’re building a content aggregator, publishing a podcast, or exposing your application’s data as feeds, bx-rss makes it incredibly simple.

Thanks To Ray Camden

I just want to thank you to Ray Camden for his contributions to this module. Thanks Ray! You rock!

Why bx-rss?

In today’s interconnected web, RSS and Atom feeds remain crucial for content distribution and syndication. From blog posts and news articles to podcasts and video channels, feeds power how content flows across the internet. The bx-rss module brings enterprise-grade feed capabilities to BoxLang with an elegant, easy-to-use API.

JC-AI Newsletter #8

Thu, 30 Oct 2025 06:36:12 +0000

Fourteen days have passed, and it is time to present a fresh collection of readings that could influence developments in the field of artificial intelligence.

This newsletter focuses on examining how AI enhances productivity through enterprise studies, agentic system architecture, attack vectors, Model Context Protocol (MCP) implementation, Agent-to-Agent (A2A) protocol, Java code generation within IDEs, LLM benchmarking methodologies, and the security challenges arising from increased AI-LLM adoption.

The world influenced by LLM is changing very quickly, let’s start…

Agent Memory with Spring AI & Redis

Wed, 23 Jul 2025 16:34:04 +0000

You’re building an AI agent with memory using Spring AI and Redis. Unlike traditional chatbots that forget previous interactions, memory-enabled agents can recall past conversations and facts. It works by storing two types of memory in Redis: short-term (conversation history) and long-term (facts and experiences as vectors), allowing agents to provide personalized, context-aware responses.

LLMs respond to each message in isolation, treating every interaction as if it’s the first time they’ve spoken with a user. They lack the ability to remember previous conversations, preferences, or important facts.

Kotlin adoption inside ING, five years later

Wed, 02 Jul 2025 06:21:47 +0000

TL;DR: Five years after its introduction Kotlin adoption inside ING keeps growing year after year, with a current adoption rate of just over 11%. We were also featured as one of the user stories for the KotlinConf 2025 Keynote.

Five years ago, Hielke and I wrote one of the first blogs of this account about being the first team to put Kotlin on production at ING. The article generated some interest and to this day it is still present as one of the Kotlin website case studies.

Semantic Search with Spring Boot & Redis

Mon, 05 May 2025 15:35:55 +0000

TL;DR: You’re building a semantic search app using Spring Boot and Redis. Instead of matching exact words, semantic search finds meaning using Vector Similarity Search (VSS). It works by turning movie synopses into vectors with embedding models, storing them in Redis (as a vector database), and finding the closest matches to user queries.

A traditional searching system works by matching the words a user types with the words stored in a database or document collection. It usually looks for exact or partial matches without understanding the meaning behind the words.

Review of Junie, a coding agent by JetBrains – Revie

Wed, 26 Feb 2025 01:38:47 +0000

Other languages: Español 한국어 Português 中文

Recently, I talked about Duplicate Finder on the Foojay Podcast hosted by Frank Delporte. We briefly touched upon implementing support for other formats, and Frank asked if I’m planning on adding AsciiDoc, as it could be useful for his technical writing at Azul.

We agreed to think about adding the support soon. At the same time I got access to Junie, a newly announced coding agent by JetBrains, which is currently in early access. After a while, a thought came to me that this is a great opportunity to try it in action.

A solution to the problem of cluster-wide CRDs

Thu, 30 Jan 2025 11:55:14 +0000

I’m an average Reddit user, scrolling much more than reading or interacting. Sometimes, however, a post rings a giant red bell. When I stumbled upon If you could add one feature to K8s, what would it be?, I knew the content would be worth it.

The most voted answer is:

Namespace scoped CRDs

A short intro to CRDs

Kubernetes comes packed with existing objects, such as Pod, Service, DaemonSet, etc., but you can create your own: the latter are called Custom Resource Definitions. Most of the time, s are paired with a custom controller called an operator. An operator subscribes to the lifecycle events of CRD(s). When you act upon a CRD by creating, updating, or deleting it, Kubernetes changes its status, and the operator gets notified. What it does depends on the nature of the CRD.

Java Server and Rust Client Built with Generated Networking Code

Fri, 04 Oct 2024 11:58:05 +0000

FEPCOS-J: Implementing a Java Server and a Rust Client without Manual Network Programming

FEPCOS-J allows declaratively implementing a Java server and generating its profile, which, for example, can be used to generate the networking code of a Rust client.

Introduction

As I have shown in a previous post [1] and a video [2], the FEPCOS-J development tool [3] prototypically implements a Java language extension that allows implementing a client-server application in Java without the need for manual network programming.

Implementing the Idempotency-Key specification on Apache APISIX

Mon, 02 Sep 2024 20:58:24 +0000

Recently, I wrote an analysis of the IETF Idempotency-Key specification. The specification aims to avoid duplicated requests.

In short, the idea is for the client to send a unique key along with the request:

If the server doesn’t know the key, it proceeds as usual and then stores the response
If the server knows the key, it short-circuits any further processing and immediately returns the stored response

This post shows how to implement it with Apache APISIX.

Allocation Profiling in Java

Fri, 09 Aug 2024 08:44:59 +0000

Read in other languages : 中文 Español Português

We often find ourselves in situations when code is not working properly, and we have no idea where to even begin investigating.

Can’t we just stare at the code until the solution eventually comes to us? Sure, but this method probably won’t work without deep knowledge of the project and a lot of mental effort. A smarter approach would be to use the tools you have at hand. They can point you in the right direction.

JavaFX Nodes versus Canvas

Wed, 07 Aug 2024 08:22:31 +0000

Recently I was working on an article about Azul Zulu with JavaFX support for ARM systems, like the Raspberry Pi. As you can see in this video, I found out my little test application with a lot of “bouncing balls” started losing performance on the Raspberry Pi with more than 1000 of those balls.

Of course, having that high number of visual components in a typical JavaFX user interface would be a badly designed application. Imagine a long registration form with that number of input fields and labels… it would drive your users crazy.

Client-server application in Java: Easy with FEPCOS-J – Video.

Tue, 30 Jul 2024 11:51:04 +0000

This is a result of the FEPCOS-Project, aka @FepcosInfo; #FepcosJ_blog5.

See how FEPCOS-J relieves developers of the network programming required to implement a client-server application in Java.
External link to : G. Fuchs: Video: Easy Implementation of a Client-Server Application in Java with FEPCOS-J; On: YouTube, FEPCOS-Project (@FepcosInfo); 29-July-2024; https://youtu.be/qtPP7kZbriQ.
Impression of the above-linked video: FEPCOS-J provides annotations like @AYSpec, @In, @Out, and @Behavior for programming a client-server application in Java. Watch the video for a complete example application of FEPCOS-J.

A Beginner's Guide to IntelliJ Profiler

Thu, 04 Jul 2024 06:26:35 +0000

Read in other languages: 中文 Español Português

Sometimes your app works, but you want to increase performance by boosting its throughput or reducing latency. Other times, you just want to know how code behaves at runtime, determine where the hot spots are, or figure out how a framework operates under the hood.

This is a perfect use case for profilers. They offer a bird’s eye view of arbitrarily large execution chunks, which helps you see problems at scale.

Hack a Java application with the debugger

Thu, 13 Jun 2024 04:58:03 +0000

Read in other languages: 中文 Español Português

Back in the day, computer games were different. Not only have graphics and mechanics evolved since, but there’s also one characteristic that doesn’t seem very common in games today: nearly all of them had cheat codes.

Cheat codes were sequences of keys that would give you something extraordinary, such as infinite ammo or the ability to walk through walls. The most common and powerful of them was ‘god mode’ – it made you invincible.

Workflow, From Stateless To Stateful

Wed, 05 Jun 2024 06:11:38 +0000

A (long) time ago, my first job consisted of implementing workflows using the Staffware engine. In short, a workflow comprises tasks; an automated task delegates to code, while a manual task requires somebody to do something and mark it as done. Then, it proceeds to the next task - or tasks.

Here’s a sample workflow:

The above diagram uses Business Process Model and Notation. You can now design your workflow using and run it with compatible workflow engines.

Task scheduler in Java: background job processing with JobRunr

Wed, 22 May 2024 11:05:04 +0000

What is JobRunr

Task scheduler in Java

JobRunr is an open-source Java library for task scheduling and distributed background job processing. It offers an effortless way to perform background tasks using only Java 8 lambdas.

Whether it is a fire-and-forget , scheduled or recurring job , JobRunr analyzes the lambda and stores the metadata needed to process the job in a database. This simple architecture, with a few other mechanisms, allows a job to be executed on any available server running your application (👋 k8s).

Diagnosing user-reported issues using WireQuery

Mon, 13 May 2024 07:11:04 +0000

As a developer, I’ve often struggled with diagnosing user-reported issues, which is often caused by a lack of information to reproduce the problem. While a ticket may contain a screenshot of the problem and a description, it often does not portray the complete picture. For example: what did the user do that led up to the issue? What endpoints were called from the frontend, and how did they respond? What did the underlying systems communicate? Etc.

Debug Without Breakpoints – Guide to IntelliJ IDEA's Pause

Mon, 22 Apr 2024 06:59:28 +0000

Read in other languages: 中文 Español Português

In a typical debugging scenario, you would set breakpoints to tell the debugger when to suspend your program. A breakpoint usually corresponds to the moment that marks the starting point of the further investigation.

However, in some situations you aren’t certain about where to set a breakpoint. Other times, you might prefer to suspend the program at a particular time rather than aiming at a specific line.

Multithreaded server in Java: That's easy with FEPCOS-J.

Thu, 21 Mar 2024 08:38:28 +0000

FEPCOS-J (4) Easy programming of a multithreaded TCP/IP server in Java

FEPCOS-J prototypically implements a Java language extension that allows the realization of a multithreaded TCP/IP server in Java without thread or network programming.

Please help me to make FEPCOS-J a Free/Libre and Open-Source Software (FLOSS).

Introduction

FEPCOS-J [1] is a Java development tool that prototypes a Java language extension for declarative programming of networked systems. See my previous posts for details [2, 3, 4].

Localize applications with AI

Wed, 20 Mar 2024 08:50:29 +0000

Read in other languages: 中文 Español Português

Ever wondered if AI can localize an entire project? In this article, we follow the process end-to-end using the Spring Petclinic as an example. We prepare the project for localization, automate the translation using Python and DeepL, and analyze the results

Whether you are thinking of localizing your project or just learning how to do that, AI might help you. It offers a cost-efficient entry point for experiments and automations.

From Kotlin Scripting to Python

Thu, 07 Mar 2024 01:04:15 +0000

GitHub offers a way to customize one’s profile by allowing one to create a README in a specific repository, named as your profile, e.g. , nfrankel/nfrankel. A couple of years ago, I automated the update of my GitHub profile with up-to-date info: my latest blog posts, my upcoming talks, and the last recorded YouTube talk. I took the time to document how to do it on this blog.

At the time, I chose Kotlin scripting because I was proficient enough in Kotlin, but I wanted to learn the scripting part. Over the years, I became more and more dissatisfied with the solution. I recently moved away from Kotlin Scripting to Python. In this post, I want to explain my reasons and document the migration.