Martin on Martin Ahrer

Java 25 major language and API improvements

Tue, 30 Sep 2025 00:00:00 +0000

Java ㉕ has been released in September 2025.

The following content is summarizing the most important changes to the Java API, the Java language, and the JVM introduced with Java Java ㉕.

For a more complete overview, follow the links in the following sections referring to the official Oracle release documents.

Java 24 major language and API improvements

Wed, 27 Aug 2025 00:00:00 +0000

Java ㉔ has been released in March 2025.

The following content is summarizing the most important changes to the Java API, the Java language, and the JVM introduced with Java Java ㉔.

For a more complete overview, follow the links in the following sections referring to the official Oracle release documents.

Java 23 major language and API improvements

Tue, 26 Aug 2025 00:00:00 +0000

Java ㉓ has been released in September 2024.

The following content is summarizing the most important changes to the Java API, the Java language, and the JVM introduced with Java ㉓.

For a more complete overview, follow the links in the following sections referring to the official Oracle release documents.

OpenTelemetry Backend

Sat, 29 Mar 2025 00:00:00 +0000

The previous post introduced OpenTelemetry and the OpenTelemetry collector (aka otel-collector) which is acting as gateway to the backends persisting emitted log, metrics, and trace data.

With this post we have a more detailed look at the collector’s configuration and how it connects to the various databases

Spring Boot OpenTelemetry

Fri, 14 Mar 2025 00:00:00 +0000

As applications and architectures become increasingly complex, monitoring application health is more critical than ever. Developers, support teams, and site reliability engineers need real-time insights into performance metrics, logs, and execution traces to ensure smooth operations.

Traditionally, achieving this required integrating multiple frameworks and tools for data collection, analysis, and visualization—often leading to fragmented solutions.

Building Docker Images with bake

Tue, 03 Dec 2024 00:00:00 +0000

Platform engineers and build pipeline engineers constantly are faced with the challenge of building container images for providing images to be used as application base or for running pipeline tasks. Probably such images have to be provided as multiple variants for multiple versions of software packages to be included.

Docker Multiplatform Build

Thu, 12 Sep 2024 00:00:00 +0000

The Arm CPU architecture is getting more and more popular even on desktop developer devices.

A comparative analysis of Arm, AMD, and Intel costs in the Amazon cloud has shown that Graviton2 processors can be significantly more cost-efficient than other platforms. The study compared the 16xlarge instances based on the m6g (Graviton2, Arm), m5a (EPYC1, AMD), and m5n (Xeon Cascade Lake, Intel) for the 64-vCPU count. Not only are the Arm-based instances cheaper than AMD and Intel, they can achieve 40% better performance per dollar when translating the time to completion of SPEC tests to hours and multiplying the result by hourly cost.

— https://bell-sw.com/blog/application-cost-reduction-with-arm-servers

Java 22 major language and API improvements

Tue, 10 Sep 2024 00:00:00 +0000

Java 22 has been released in March 2024.

The following content is summarizing the most important changes to the Java API, the Java language, and the JVM introduced with Java 22.

For a more complete overview, follow the links in the following sections referring to the official Oracle release documents.

Java 21 major language and API improvements

Mon, 09 Sep 2024 00:00:00 +0000

Java 21 has been released in September 2023.

The following content is summarizing the most important changes to the Java API, the Java language, and the JVM introduced with Java 21.

For a more complete overview, follow the links in the following sections referring to the official Oracle release documents.

Java 20 major language and API improvements

Fri, 06 Sep 2024 00:00:00 +0000

Java 20 has been released in March 2023.

The following content is summarizing the most important changes to the Java API, the Java language, and the JVM introduced with Java 20.

For a more complete overview, follow the links in the following sections referring to the official Oracle release documents.

Java 19 major language and API improvements

Mon, 02 Sep 2024 00:00:00 +0000

Java 19 has been released in September 2022.

The following content is summarizing the most important changes to the Java API, the Java language, and the JVM introduced with Java 19.

For a more complete overview, follow the links in the following sections referring to the official Oracle release documents.

Java 18 major language and API improvements

Thu, 29 Aug 2024 00:00:00 +0000

Java 18 has been released in March 2022.

The following content is summarizing the most important changes to the Java API, the Java language, and the JVM introduced with Java 18.

For a more complete overview, follow the links in the following sections referring to the official Oracle release documents.

Java 17 major language and API improvements

Mon, 26 Aug 2024 00:00:00 +0000

Java LTS Release Adoption

Before we go into details of the enhancements and additions of Java ⑰ lets briefly look at new relic’s yearly State of the Java Ecosystem 2024 report.

Even though Java ⑰ LTS was released in September 2021, in 2023 only ~19% of the projects have been using it. Java ⑧ still had a share of 33%. and Java ⑪ was the dominant release with ~56%.

Java 16 major language and API improvements

Sun, 25 Aug 2024 00:00:00 +0000

Java ⑯ has been released in March 2021.

The following content is summarizing the most important changes to the Java API, the Java language, and the JVM introduced with Java ⑯.

For a more complete overview, follow the links in the following sections referring to the official Oracle release documents.

Java 15 major language and API improvements

Fri, 23 Aug 2024 00:00:00 +0000

Java ⑮ has been released in September 2020.

The following content is summarizing the most important changes to the Java API, the Java language, and the JVM introduced with Java ⑮.

For a more complete overview, follow the links in the following sections referring to the official Oracle release documents.

Java 14 major language and API improvements

Thu, 22 Aug 2024 00:00:00 +0000

Java ⑭ has been released in March 2020.

The following content is summarizing the most important changes to the Java API, the Java language, and the JVM introduced with Java ⑭.

For a more complete overview follow the links in the following sections referring to the official Oracle release documents.

Java 13 major language and API improvements

Thu, 08 Aug 2024 00:00:00 +0000

Java ⑬ has been released in September 2019.

The following content is summarizing the most important changes to the Java API, the Java language, and the JVM introduced with Java ⑬.

For a more complete overview, follow the links in the following sections referring to the official Oracle release documents.

Java 12 major language and API improvements

Tue, 06 Aug 2024 00:00:00 +0000

Java ⑫ has been released in March 2019.

The following content is summarizing the most important changes to the Java API and the Java language introduced with Java ⑫.

For a more complete overview, follow the links in the following sections referring to the official Oracle release documents.

Java 11 major language and API improvements

Wed, 24 Jul 2024 00:00:00 +0000

Java LTS Release Adoption

Before we go into details of the enhancements and additions of Java ⑪ lets briefly look at new relic’s yearly State of the Java Ecosystem 2024 report.

Even though Java ⑪ LTS was released in 2018, in 2020 only ~11% of the projects have been using it. Java ⑧ was still the dominant Java release. In 2023 usage was still at 33% and only dropped to around 28% in 2024.

Java 10 major language and API improvements

Fri, 19 Jul 2024 00:00:00 +0000

Java ⑩ has been released in March 2018.

The following content is summarizing the most important changes to the Java API and the Java language introduced with Java ⑩.

For a more complete overview follow the links in the following sections referring to the official Oracle release documents.

Java 9 major language and API improvements

Tue, 16 Jul 2024 00:00:00 +0000

Java ⑨ has been released in September 2017 and is the first release starting a new release cycle with a new release every 6 months.

The following content is summarizing the most important changes to the Java API and the Java language introduced with Java 9.

Generating AsciiDoc using a Java annotation processor

Mon, 15 Jul 2024 00:00:00 +0000

In the past I have helped a number of customers with their journey of migrating their Java 8 based applications to Java 17 (and Java 21 later on). I came up with the idea of creating a slide deck covering the major Java language and API improvements to teach my customers and give some motivation to move on to the latest Java releases.

Hashicorp Nomad native workload

Sat, 25 Feb 2023 00:00:00 +0000

Earlier this week I presented my talk "Need something simpler than Kubernetes?" to the CNCF Linz community.

This post is a follow-up explaining how to deploy a native workload to Nomad. Nomad is unique because of its hybrid support for many types of workload. While Kubernetes has been designed for managing container-only workloads, Nomad’s pluggable task drivers allows scheduling container, Java, native (raw), QEMU/KVM, etc. workloads.

Detect and alert common vulnerabilities and exposures (CVE) in 3rd-party dependencies

Wed, 03 Aug 2022 00:00:00 +0000

Using 3rd-party libraries makes developer’s lives so much easier but can turn them into a nightmare when they are unmanaged and we don’t have a good understanding what is being used in a project or even a larger organization.

A few months ago we have seen quite a few popular frameworks widely used in many software products being hit by severe CVE (common vulnerabilities and exposures).

Hashicorp Nomad with Consul service discovery

Tue, 26 Jul 2022 00:00:00 +0000

With my previous post I demonstrated how simple it is to connect services through Nomad’s service discovery support. I promised to follow-up showing this with Consul providing the service registry and use Consul’s service discovery.

Le’s look into the service stanza documentation. The provider key allows 2 different values. We already used nomad implementing the Nomad service registry. Before Nomad 1.3 only consul was a supported service registry. This was the default for this key and would register the service with the Consul service registry. So we would go ahead and just would set provider = "consul" for the api and the db service.

Hashicorp Nomad service discovery

Mon, 25 Jul 2022 00:00:00 +0000

With the recently released Nomad 1.3 a service registry backed by Nomad was added. This is making building complex services dependent on others really easy. Earlier we typically would have added Hashicorp Consul as service registry. In a production environment that would have meant to a add a Consul cluster running along with the Nomad cluster. Obviously this comes with some costs even when running such a cluster is really made simple by Hashicorp.

Introduction to Hashicorp Nomad

Wed, 20 Jul 2022 00:00:00 +0000

In the past 2 years I successfully architected and developed a new product for a customer and brought it to production. This product uses Hashicorp’s job scheduler Nomad for managing workload.

Nomad is an excellent alternative to Kubernetes. It is known for its simplicity in regard to usage and maintainability and allows to schedule containerized and non-containerized applications.

TDD for infrastructure with ignite + firecracker

Thu, 01 Oct 2020 00:00:00 +0000

This is the last post in the series of posts about TDD for infrastructure. If you wanted to follow along I recommend first reading TDD for infrastructure with Vagrant and then TDD for infrastructure with footloose.

In the previous post TDD for infrastructure with footloose I explored weaveworks' footloose to start containers that look like virtual machines. Containers do no quite cope with the isolation that a real virtual machine can provide. So in case we must use a real virtual machine we can go back to the approach with VirtualBox (or any other product) or investigate into other options.

TDD for infrastructure with footloose

Tue, 01 Sep 2020 00:00:00 +0000

In the previous post TDD for infrastructure with Vagrant I explored Vagrant, VirtualBox and Chef Inspec for implementing a simple workflow for test driven development of infrastructure code. I showed that using virtual machines as target machines for testing is just not fast enough and probably hard to run in a build environment.

blog

Tue, 18 Aug 2020 00:00:00 +0000

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Impressum

Tue, 18 Aug 2020 00:00:00 +0000

Martin Ahrer

Libenauerstraße 69
4040 Lichtenberg
Österreich

- office at martinahrer.at
- +43 699 11668668

UID (VAT): ATU58077823

Behörde gem. ECG (E-Commerce Gesetz): Bezirkshauptmannschaft Urfahr-Umgebung
Anwendbare Rechtsvorschriften: http://www.ris2.bka.gv.at

Informationspflicht lt. §5 E-Commerce Gesetz, §14 Unternehmensgesetzbuch bzw. §63 Gewerbeordnung und Offenlegungspflicht lt. §25 Mediengesetz

Martin Ahrer

Tue, 18 Aug 2020 00:00:00 +0000

Martin is a software engineer with 25+ years of experience as a professional software engineer. He has worked for numerous companies in the healthcare and financial industry in Europe, Asia and the United States.

Currently his focus is on continuous delivery, helping customers automating their software delivery processes. This automation takes off with the first commit to a code repository and finishes when a feature is deployed to a life production system and generates business value. He has a strong expertise in container technology (Docker) and has successfully implemented fully container driven software build pipelines for his customers. Martin is also proficient in architecting distributed systems.

TDD for infrastructure with Vagrant

Sat, 01 Aug 2020 00:00:00 +0000

Introduction

For many years (almost decades) developers have been practicing test driven development and write tests to get confidence that their code works.

However, with the rise of infrastructure as code where DevOps engineers try to describe infrastructure provisioning using code, this is something that is not observed generally. In many situations I have encountered infrastructure that

Google Container Tools - Jib

Sun, 19 Apr 2020 00:00:00 +0000

With this post we close the series of articles taking a deep dive on building Docker images. We look at a building Docker images for running Java applications in a Docker container with Jib which is part of the Google Container Tools.

Jib

Jib is highly opinionated about building Java Docker containers using Maven or Gradle as build tool. So it offers plugin support for the above mentioned build tools.

Docker BuildKit

Thu, 16 Apr 2020 00:00:00 +0000

In the previous blog post of the building docker images series we had a look at Docker image build pipelines. We revealed typical problems and looked at how to overcome some by utilizing multistage builds.

In part 4 of this series we work with an addition to the Docker tooling which is BuildKit.

Docker image build pipeline

Fri, 30 Aug 2019 00:00:00 +0000

Let’s recap what we have covered in this blog post series so far. In Building a Docker Image we had a look at the anatomy of a Docker image. And Optimizing a Docker Image shed some light on optimizations when building an image.

Optimizing a Docker Image

Tue, 20 Aug 2019 00:00:00 +0000

This post continues where we left off with Building a Docker Image. We are looking into how we can optimize the process of building a Docker image. This optimization can aim at reducing the size of images built or the time it takes for packaging an image.

Building a Docker Image

Sat, 17 Aug 2019 00:00:00 +0000

This post starts a series of articles taking a deep dive on building Docker images. But before we look at building a Docker image let’s briefly recap the essentials we need to know about container images.

A Docker image is built up from a series of layers where each layer represents an instruction in the image’s Dockerfile. When Docker materializes an image and creates a container from this image, a storage driver handles the details about the way these layers interact with each other. Different storage drivers are available, which have advantages and disadvantages in different situations (e.g. AUFS, overlay, overlay2, btrfs,zfs). All drivers have in common that they use stackable image layers and the copy-on-write (CoW) strategy for writing files.

Continuous delivery infrastructure as code

Wed, 10 May 2017 00:00:00 +0000

This is part 1 of a series of posts covering Docker in a Continuous Delivery environment.

Today I’m showing how simple it is to setup a continuous delivery build pipeline infrastructure using Docker. In an upcoming post we will look at Jenkins pipeline as code creating Docker images and running integration tests against Docker containers. The series will close with an article explaining how we can move all containers built throughout this series of posts in a Docker swarm environment.

docker-compose scripting

Tue, 07 Feb 2017 00:00:00 +0000

This time we look at managing large numbers of compose projects.

When building complex infrastructure using docker-compose we soon end in a mess of scripts for starting, updating, etc. containers. I will try to describe an approach that has helped to get this done in a very structured way.

docker-compose modularization

Mon, 06 Feb 2017 00:00:00 +0000

In this blog post we are looking into how we can create modular compose projects.

With docker-compose we can describe a bunch of containers and container related resources such as networks and volumes that make up an application. All this is usually going into a docker-compose.yml file.

Bean Mapping of Transfer Objects

Tue, 08 Mar 2016 00:00:00 +0000

In the past years I have been working on multiple projects where the so-called Data Transfer Object (short DTO) pattern has been heavily used. This is a pattern that has even been a core pattern in the JEE world. This pattern certainly has its justification for the right cases. But in many cases I have seen it applied inappropriately. This blog posting by Adam Bien, a JEE advocate, is outlining the case where it should be considered useful. However when applied, this pattern comes at the cost of additional code to maintain and some extra CPU cycles for doing the mapping.