fidzu : Java

DB changes can be streamed in real time via Oracle GoldenGate. Java applications can then consume them to validate/act on/route events without polling the DB.

Goal

Listen to real-time transactions in the DB, act on all operations within transactions, and maintain transaction boundaries with near real-time SLAs.

13 Nov 2026 3:00pm GMT

The Cookie That Never Came Back

The first call authenticated the user. The second failed.

I was integrating with a customer-provided SOAP service exposed through a single WSDL, with JAX-WS client classes generated by IBM Rational Application Developer from the WSDL and its XSDs. The first call authenticated the user and came back with a Set-Cookie header. Every call after it needed that cookie. The generated client sent none of it. Each invocation behaved as an independent conversation, and the workflow broke on its second step. No exception, no warning. Just a server that had forgotten who you are.

12 Nov 2026 5:00pm GMT

Every app that accepts photo uploads meets HEIC sooner or later. iPhones save in it by default. Neither Java nor Rust can read it out of the box, and the usual answer, libheif, is a C library: native packages in every container image, a C toolchain in the build, and a parser written in C reading files that strangers upload.

I had the problem twice, in a Java product and in a Rust one. So I went the other way: decoders written in the language itself, built and improved by AI coding agents, with me steering. Here is how it went.

12 Nov 2026 2:00pm GMT

When JDK 27 was released on 15 September 2026, most of the attention went to compact object headers and post-quantum TLS. JEP 523 received less coverage, partly because its description sounds like housekeeping: G1 becomes the default garbage collector in all environments.

For most applications, that changes nothing. For a specific class of container, it changes the collector silently, with no warning in the logs and no failure at startup.

03 Nov 2026 1:00pm GMT

GitHub's contribution calendar gives you an already iconic overview of your activity over the year. Each day has a square, and its color changes with the contribution level. And of course, those days and contributions can also be arranged into buildings, with a week becoming a small part of a city and busier weeks adding height to the skyline.

I had some spare minutes and built Quarkus Contribution City around this idea, using Java and Quarkus to generate an SVG from GitHub's contribution data. The visual inspiration came from Pink Pixel's skyline, and you can see a version with my real data on my GitHub profile. A scheduled GitHub Action updates the image at night.

02 Nov 2026 2:00pm GMT

If you have worked on a mature Java backend application, your src/main/resources/db/migration folder probably looks like a chaotic history ledger:

V1__init_schema.sql
V2__add_users_table.sql
...
V142__add_status_column.sql
V143__fix_status_typo.sql
V144__drop_old_status.sql
V145__add_missing_index.sql

29 Oct 2026 12:00pm GMT

The message left the first service at 2:14 PM and never reached the last one. Between those facts: four pipeline stages, six topics, a pub/sub API moving every record. The engineer on call had Kafdrop open, the offsets looked fine, and nobody could say which stage had eaten the record.

That gap is why we built message search for Kafdrop at a hackathon. The setup was familiar from my day job: a platform moving data between pipeline stages over a pub/sub API, with no way to ask where a message went when something breaks. Kafdrop showed partitions and offsets. It couldn't search inside the messages.

28 Oct 2026 1:00pm GMT

The Core Problem

In Part 1, we built a Quarkus MCP tool server. In Part 2, we secured it with agentgateway. In Part 3, we added distributed tracing. The architecture handles single-request tool calls well - but enterprise processes are rarely single-step.

Consider what happens when a developer tells Goose: "Migrate the users table to add an email column, then deploy the updated service to production." This triggers a chain of operations:

27 Oct 2026 6:00pm GMT

The Java compiler's job is to check whether code follows the rules of the language. Trying to remove an element from a collection that can never contain it, or using the wrong letter in a date pattern, does not break those rules, so nothing stops the code from compiling. In short, any code that follows the rules compiles, even when it does not do what its author intended.

What Is Error Prone?

Error Prone is an open-source static analysis tool that Google built to fill this gap. Unlike most static analysis tools, it does not run as a separate step; it plugs into javac as a plugin. Using the information the compiler produces while analyzing the code, it looks for patterns that follow the rules of the language but are most likely wrong, and reports them as compiler warnings or errors.

27 Oct 2026 3:00pm GMT

Modern enterprise applications must process increasing data volumes while guaranteeing low latency, high availability, and predictable performance. While relational databases are essential for transactional workloads and complex queries, some applications do not fit the relational model. Systems that manage millions of user engagements, financial events, or IoT data often need a persistence solution built for distributed environments and horizontal scalability. In these cases, ScyllaDB affords a compelling option for enterprise architects.

ScyllaDB is a high-performance, distributed NoSQL database based on the wide-column data model. Inspired by Apache Cassandra and compatible with its query language (CQL), ScyllaDB uses a shard-per-core architecture to maximize hardware efficiency and preserve consistent performance under intensive workloads. When should ScyllaDB be chosen over traditional relational databases or other NoSQL options? This article examines its column-family model, compares it with Cassandra, and shows how to integrate ScyllaDB into a Java enterprise application.

23 Oct 2026 5:00pm GMT

What does it take to build and sustain an open-source project for more than a decade? For Shai Almog, creator of Codename One, it takes a willingness to challenge conventional approaches to software development and a continued commitment to the developers who rely on the work.

I recently caught up with Shai to discuss the inspiration behind Codename One, the realities of maintaining an open-source project, and his perspective on how the Java ecosystem has evolved over the years. Check it out below!

23 Oct 2026 1:30pm GMT

If you've been following the database world lately, you'll have noticed DuckDB turning up in some unexpected places. One of the more interesting examples is pg_duckdb, a Postgres extension that embeds DuckDB directly into the Postgres process, letting analytical queries run through DuckDB's engine without leaving the database. It's a clever idea: keep your data where it is, but bring a faster analytical engine.

That got us wondering: could we do something similar with Neo4j?

20 Oct 2026 5:00pm GMT

Teams considering or committed to adopting Kotlin often plan a migration as a series of rewrites, swapping Java services for Kotlin counterparts one microservice at a time. In practice, that kind of plan tends to stall before it produces any shipped code.

Kotlin's role in the JVM ecosystem is expanding because it doesn't require that kind of commitment. Companies such as Netflix, Adobe, and DoorDash have adopted it incrementally, alongside existing JVM systems, rather than through a full rewrite. The lowest-risk starting point is tests. They give you Kotlin's language benefits, including null-safety, data classes, and expressive lambdas, without touching anything that runs in production.

20 Oct 2026 2:09pm GMT

Virtual threads let us keep ordinary blocking code while many more requests wait concurrently. Under load, however, that brings three critical questions into focus:

• How much work do we admit? Cheap threads can still build an expensive queue.
• What belongs inside a lock? A sleeping lock holder still makes everyone else wait.
• Who stops abandoned work? A caller's timeout does not cancel its task.

The examples below isolate these questions with separate before-and-after programs. Each program is complete: save its code block under the filename shown and run the accompanying command, without arguments. All you need is JDK 25. They use its compact source-file syntax, so no class declaration, build tool, external library, or preview flag is required.

20 Oct 2026 1:00pm GMT

Microservices do not eliminate transactions. They force architects to decide where a transaction should end.

That decision is harder than it sounds. A business operation that was once handled inside a single database transaction may cross several services after decomposition. An order can involve inventory, payment, pricing, customer limits, audit history, and notification. The architecture may divide these responsibilities cleanly, but the business still sees one operation: place the order.

20 Oct 2026 12:00pm GMT

If you've sat through more than one architecture review, you've probably sat through a protracted Kotlin-versus-Java debate that goes nowhere. The team spends weeks comparing Kotlin's concise syntax to Java's maturity, runs a poll on developer preference, and produces a decision matrix nobody fully trusts. Then the meeting ends, and nothing changes, because nobody agreed on what problem they were actually trying to solve.

Choosing between infrastructure instruments, such as Kotlin and Java, is an investment decision, and like any investment decision, it needs a thesis. Four business pressures should drive the discussion: time-to-market, operational risk, talent economics, and cross-platform consistency.

16 Oct 2026 7:56pm GMT