A Java geek

Feedback on checked exceptions and lambdas

I got a lot of interesting feedback on Checked exceptions and lambdas. Let’s start with my own: after writing the post, I realized I had written a similar post some time ago. Mistakes I made I made a mistake in the code regarding Apache Commons Lang 3, where I mistakenly used the recover() function, which is actually from Vavr. Apache Commons Lang provides a regular utility function, which mimics the custom code we wrote last week.

Java

From a JAR to a full-fledged MacOS app

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. The problem When launching the UberJAR, I couldn’t see the network volumes.

Java

Checked exceptions and lambdas

Java’s checked exceptions were a massive improvement over C’s error-handling mechanism. As time passed and experience accumulated, we collectively concluded that we weren’t there yet. However, Java’s focus on stability has kept checked exceptions in its existing API. Java 8 brought lambdas after the 'checked exceptions are great' trend. None of the functional interface methods accepts a checked exception.

Technical

From Cloudflare Zero-trust to Tailscale

I have spent some time last year implementing Cloudflare Tunnels on my Home Assistant and my Synology NAS. On Mastodon, I had not one but two commenters advertising for Tailscale: Post by @frankel@mastodon.top View on Mastodon I decided to give it a try and migrate my servers and devices to Tailscale. In this post, I want to describe how I did. Thanks to Heiko Does and higgins for prompting me to look further! What is Tailscale, how and why?

Miscellaneous

2025 in retrospective

From the beginning, the focus of this blog has been technical, very rarely organizational. I broke this unwritten rule once in 2015. I began writing retrospectives in 2023 on the year that had passed. Let’s continue the tradition, but with a wider scope than before. The situation warrants it. More chaos It’s a hard realization to admit, but the world is spiraling deeper and deeper into chaos.

Miscellaneous

YOW! 2025

I have been eyeing the YOW! conferences for probably more than a decade. They occur in Australia, and feature top industry experts. I was thus overjoyed when they invited me to speak on the YOW! tour earlier this year. Here’s a summary of my amazing time there. My participation YOW! takes place in three different cities: Melbourne, Brisbane, and Sidney. I presented my brand new talk on WebAssembly on Kubernetes in each city.

Development

Yet another Rust ownership tutorial

One of the most important concepts to master in Rust is ownership and borrowing. Tons and tons of articles are solely dedicated to this narrow subject. This one tries to explain the concept with examples. I hope it helps you. Ownership is a set of rules that govern how a Rust program manages memory. All programs have to manage the way they use a computer’s memory while running.

Technical

My second Cloudflare Tunnel

I decided to stop using Twitter, but for my own content and supporting Ukraine against its barbarian invaders, I understood the contemporary media landscape was quite fragmented. I bet on Mastodon, Bluesky, and LinkedIn. My flow is the following: when I read a piece I find interesting, I schedule it for publication.

Development

My first real Rust project

I have been learning Rust for a couple of years, and using it for pet projects and demos alike. Working for a JVM-heavy company, I thought it would be my fate forever. Last week, I had a nice surprise: I convinced my management that using Rust for a particular project was the right choice. It’s not a huge project, but I want to describe my experience using Rust in a 'real' project. The project Our main software platform has baked-in health sensors for monitoring.

Nicolas Fränkel's blog