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.

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.

Mon, 01 Jan 0001 00:00:00 +0000

Build tool chain container images

export DOCKER_BUILDKIT=1
docker image build -t martinahrer/ansible:alpine -f Dockerfile_ansible .
docker image build -t martinahrer/footloose:alpine -f Dockerfile_footloose .
docker image build -t martinahrer/inspec:alpine -f Dockerfile_inspec .

Run all pipeline steps.

cd src/main/
drone exec --trusted drone.io/.drone.yml

Run the pipeline test step.

Mon, 01 Jan 0001 00:00:00 +0000

Start consul agent (in dev mode)

consul agent -dev -config-file server.hcl
open http://localhost:8500

Mon, 01 Jan 0001 00:00:00 +0000

Start nomad server and client agents

nomad agent -config server.hcl
nomad agent -config client1.hcl
nomad agent -config client2.hcl
nomad agent -config client3.hcl
open http://localhost:4646

The agents have no explicit consul configuration. So in case consul is running with default settings, nomad will connect using the defaults (https://www.nomadproject.io/docs/configuration/consul).

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java JVM. See the Java 18 release notes.

With JEP-400, now UTF-8 is the default charset of the standard Java APIs.

In JDK 17 and earlier, the default charset is determined when the Java runtime starts. On macOS, it is UTF-8 except in the POSIX C locale. On other operating systems, it depends upon the user’s locale and the default encoding, e.g., on Windows, it is a codepage-based charset such as windows-1252 or windows-31j.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 18 release notes. See Java Language Updates for Java SE 18.

Java 18 is introducing the following language enhancements as developer preview.

JEP 420 is continuing with Pattern Matching for switch.

Mon, 01 Jan 0001 00:00:00 +0000

With a snippet region defined we can include a fragment of compileable and tested code.

Snippet Include

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/eighteen/tooling/JavaDocSnippetTag.java[tag=snippetInclude]

With a snippet tag we can just inline code. There is no need to escape or use HTML.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java tooling. See the Java 18 release notes.

Java 18 is introducing the following tooling enhancements.

JEP 408 is adding the jwebserver tool that can serve static files and support the HEAD and GET methods. This is simplifying situations where a simple web server is needed for example for testing and eliminating the need for external dependencies. In case a more customized web server is required, we can use the implementations from the package com.sun.net.httpserver which constitutes the base for jwebserver.
JEP 413 is adding support to include Java code snippets either from external sources of inline snippets. Nicolai Parlog has a pretty decent summary of some of the features builtin. See https://nipafx.dev/inside-java-newscast-20/#code-in-javadoc

Mon, 01 Jan 0001 00:00:00 +0000

To Array

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/eleven/api/CollectionApi.java[tag=toArray]

Mon, 01 Jan 0001 00:00:00 +0000

Files.readString() and Files.writeString()

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/eleven/api/FilesApi.java[tag=writeStringAndReadString]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 11 release notes.

Unresolved directive in <stdin> - include::PredicateApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::StringApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::CollectionApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::FilesApi.adoc[leveloffset=+1]

Mon, 01 Jan 0001 00:00:00 +0000

Before Java 11 we had to use Predicate::negate and it was not possible to use a method reference. With Predicate::not we can use method references and Predicate::not reads more natural.

Not

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/eleven/api/PredicateApi.java[tag=not]

Mon, 01 Jan 0001 00:00:00 +0000

Lines

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/eleven/api/StringApi.java[tag=lines]

With String::lines we can split any multi line String into a stream of lines.

Strip

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/eleven/api/StringApi.java[tag=strip]

String::strip is similar to String::trim but with Unicode support. String also has a stripLeading and stripTrailing method.

Mon, 01 Jan 0001 00:00:00 +0000

Lambda variable without type with {java10}

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/eleven/lang/LambdaLocalVariable.java[tag=beforeJava11]

Lambda variable with type with {java10}

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/eleven/lang/LambdaLocalVariable.java[tag=withTypeBeforeJava11]

The type is inferred from the initializer.

With multiple lambda variables we have to use var for all or none. Also it is not possible to mix var with explicit types.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 10 release notes.

Unresolved directive in <stdin> - include::LambdaLocalVariable.adoc[leveloffset=+1]

Mon, 01 Jan 0001 00:00:00 +0000

Is Empty

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/fifteen/api/CharSequenceApi.java[tag=isEmpty]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 15 release notes.

Unresolved directive in <stdin> - include::CharSequenceApi.adoc[leveloffset=+1]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 15 release notes.

With JEP 378, Text Blocks introduced in Java 13 are now moving from preview state to general availability.

Java 15 is introducing the following language enhancements as developer preview.

Mon, 01 Jan 0001 00:00:00 +0000

Multiline Text Block

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/fifteen/lang/TextBlock.java[tag=multilineTextBlock]

Mon, 01 Jan 0001 00:00:00 +0000

Currency Instance

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/fourteen/api/AccountingCurrencyFormatSupport.java[tag=currencyInstance]

See the Unicode Currency Format Identifier.

Mon, 01 Jan 0001 00:00:00 +0000

Readable Null Pointer Exception Message

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/fourteen/api/NullPointerExceptions.java[tag=readableNullPointerExceptionMessage]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 14 release notes.

Unresolved directive in <stdin> - include::NullPointerExceptions.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::AccountingCurrencyFormatSupport.adoc[leveloffset=+1]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java JVM. See the Java 14 release notes.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See Java Language Changes for Java SE 14

Java 14 is introducing the following language enhancements as developer preview.

JEP 305 is introducing Pattern Matching for instanceof and is eliminating boilerplate code.
JEP 359 introduces Record to reduce repetitive boilerplate code in data model POJOs.

Mon, 01 Jan 0001 00:00:00 +0000

Switch Expression

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/fourteen/lang/SwitchExpressions.java[tag=switchExpression]

The compiler warns when cases are not exhausted. A default clause is required. However, for enum switch expressions that cover all known constants, the compiler inserts an implicit default clause.

Switch Expression Yield

Mon, 01 Jan 0001 00:00:00 +0000

By applying a filter predicate we can adapt a collector to accept only elements matching a predicate.

Filtering

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/CollectorsApi.java[tag=filtering]

With the new flatMapping method a stream of streams or stream of collections a collector is adapted to return a flattened result.

Mon, 01 Jan 0001 00:00:00 +0000

Factory methods have been added to the Collections class for simplifying list creation.

Empty list with {java8}

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ImmutableListFactory.java[tag=immutableEmptyList]

Empty list with {java9}

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ImmutableListFactory.java[tag=immutableEmptyListJava9]

List with {java8}

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ImmutableListFactory.java[tag=immutableListJava8]

List with {java9}

Mon, 01 Jan 0001 00:00:00 +0000

Factory methods have been added to the Collections class for simplifying map entry creation.

Immutable Empty Map

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ImmutableMapEntryFactory.java[tag=immutableEmptyMap]

Immutable Map

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ImmutableMapEntryFactory.java[tag=immutableMap]

Mon, 01 Jan 0001 00:00:00 +0000

Factory methods have been added to the Collections class for simplifying map creation.

Empty map with {java8}

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ImmutableMapFactory.java[tag=immutableEmptyMapJava8]

Empty map with {java9}

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ImmutableMapFactory.java[tag=immutableEmptyMapJava9]

Map with {java8}

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ImmutableMapFactory.java[tag=immutableMapJava8]

Map with {java9}

Mon, 01 Jan 0001 00:00:00 +0000

Factory methods have been added to the Collections class for simplifying set creation.

Empty Set with {java8}

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ImmutableSetFactory.java[tag=immutableEmptySetJava8]

Empty Set with {java9}

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ImmutableSetFactory.java[tag=immutableEmptySetJava9]

Set with {java8}

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ImmutableSetFactory.java[tag=immutableSetJava8]

Set with {java9}

Mon, 01 Jan 0001 00:00:00 +0000

With Matcher.results we get a stream of all matched elements

Results

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/MatcherApi.java[tag=results]

With Matcher.replaceAll we can perform substitution of matches.

Replace All

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/MatcherApi.java[tag=replaceAll]

Mon, 01 Jan 0001 00:00:00 +0000

Methods for convenient null checking have been added to Objects class.

Require Non Null Else

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ObjectsApi.java[tag=requireNonNullElse]

Require Non Null Else Get

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/ObjectsApi.java[tag=requireNonNullElseGet]

Mon, 01 Jan 0001 00:00:00 +0000

Optional Or

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/OptionalApi.java[tag=optionalOr]

Optional If Present Or Else

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/OptionalApi.java[tag=optionalIfPresentOrElse]

Optional Stream

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/OptionalApi.java[tag=optionalStream]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 9 release notes.

Unresolved directive in <stdin> - include::CollectorsApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::ObjectsApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::MatcherApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::ImmutableListFactory.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::ImmutableMapEntryFactory.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::ImmutableMapFactory.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::ImmutableSetFactory.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::StreamApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::OptionalApi.adoc[leveloffset=+1]

Mon, 01 Jan 0001 00:00:00 +0000

Take While

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/StreamApi.java[tag=takeWhile]

We can take (accept) stream elements matching a predicate.

Drop While

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/StreamApi.java[tag=dropWhile]

We can drop stream elements matching a predicate.

Iterate

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/api/StreamApi.java[tag=iterate]

Generate a stream using an iteration.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 9 release notes.

Unresolved directive in <stdin> - include::PrivateInterfaceMethod.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::TryWithResource.adoc[leveloffset=+1]

Mon, 01 Jan 0001 00:00:00 +0000

An interface can now have private methods. These can simplify implementing default methods.

Say Hello

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/lang/PrivateInterfaceMethod.java[tag=tagname]

Mon, 01 Jan 0001 00:00:00 +0000

Before Java9

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/lang/TryWithResource.java[tag=beforeJava9]

Before Java 9 a variable referencing a resource had to be redeclared (and assigned) in the try block in order to be automatically closed.

With Java9

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nine/lang/TryWithResource.java[tag=withJava9]

Variables that are effectively final can be used in a try with resource block (and don’t have to be redeclared).

Mon, 01 Jan 0001 00:00:00 +0000

It is now possible to create pre allocated hash maps and hash sets through a set of new factory methods on Set and Map implementations.

New Hash Map

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nineteen/api/CollectionApi.java[tag=newHashMap]

New Hash Set

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nineteen/api/CollectionApi.java[tag=newHashSet]

Mon, 01 Jan 0001 00:00:00 +0000

Of Localized Pattern

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nineteen/api/DateTimeFormatterApi.java[tag=ofLocalizedPattern]

The formatted value is Sep 2022. Read more about the pattern template in the API documentation.

Append Localized

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/nineteen/api/DateTimeFormatterApi.java[tag=appendLocalized]

The formatted value is Sep 2022. Read more about the pattern template in the API documentation.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 19 release notes.

Unresolved directive in <stdin> - include::CollectionApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::DateTimeFormatterApi.adoc[leveloffset=+1]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java JVM. See the Java 19 release notes.

Class data sharing (CDS) now has an option -XX:+AutoCreateSharedArchive to automatically create or update a CDS archive for an application..

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 19 release notes. See Java Language Updates for Java SE 19.

Java 19 is introducing the following language enhancements as developer preview.

JEP 405 is starting with Record Patterns as developer preview
JEP 420 is continuing with Pattern Matching for switch.
JEP 425 is starting with Virtual Threads.
JEP 428 is starting with Structured Concurrency.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 17 release notes. See Java Language Updates for Java SE 17.

With JEP 409 Sealed Classes are now leaving preview state and are finally available for production.

Java 17 is introducing the following language enhancements as developer preview.

Mon, 01 Jan 0001 00:00:00 +0000

Sealed Class Permits

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/seventeen/lang/SealedClasses.java[tags=Shape;Ellipsis;Circle;Rectangle]

The new keyword permits declares which subclasses are allowed.
Subclasses may be sealed,
final or,
non-sealed

Sealed Class Subclasses In Same Sourcefile

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/seventeen/lang/SealedClasses.java[tags=Ellipsis;Circle]

The permits declaration can be omitted when
the subclasses are in the same source file.

Mon, 01 Jan 0001 00:00:00 +0000

Day Period Support

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/sixteen/api/DayPeriodSupport.java[tag=dayPeriodSupport]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 16 release notes.

Unresolved directive in <stdin> - include::DayPeriodSupport.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::StreamApi.adoc[leveloffset=+1]

Mon, 01 Jan 0001 00:00:00 +0000

Stream.toList()

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/sixteen/api/StreamApi.java[tag=toList]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 16 release notes. See Java Language Updates for Java SE 16.

With JEP 394, Pattern Matching for instanceof introduced in {java14} is moving from preview state to final availability.

With JEP 395, Record introduced in {java14} is moving from preview state to final availability.

Mon, 01 Jan 0001 00:00:00 +0000

Pattern Matching For Instanceof

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/sixteen/lang/PatternMatchingForInstanceof.java[tag=patternMatchingForInstanceof]

Pattern matching eliminates a required type conversion (type cast).

Mon, 01 Jan 0001 00:00:00 +0000

See https://docs.oracle.com/en/java/javase/16/language/records.html

Record

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/sixteen/lang/Record.java[tag=record]

A record is implicitly final,
has a canonical constructor equal to the header,
has a toString(), equals(), and hashCode() method.
Each member has an accessor method, e.g x() or y().

Compact Canonical Constructor

Mon, 01 Jan 0001 00:00:00 +0000

To Unmodifiable List

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/ten/api/CollectorsApi.java[tag=toUnmodifiableList]

With Collectors.toUnmodifiableList() we can now convert a list into an immutable list.

To Unmodifiable Set

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/ten/api/CollectorsApi.java[tag=toUnmodifiableSet]

With Collectors.toUnmodifiableSet() we can now convert a set into an immutable set.

Mon, 01 Jan 0001 00:00:00 +0000

Copy Of

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/ten/api/ListApi.java[tag=copyOf]

With List.copyOf we can now create an immutable copy of a list.

Mon, 01 Jan 0001 00:00:00 +0000

Copy Of

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/ten/api/MapApi.java[tag=copyOf]

With Map.copyOf we can now create an immutable copy of a list.

Mon, 01 Jan 0001 00:00:00 +0000

Or Else Throw

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/ten/api/OptionalApi.java[tag=orElseThrow]

A argumentless method Optional.orElseThrow() that throws a NoSuchElementException has been added.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 10 release notes.

Unresolved directive in <stdin> - include::ListApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::MapApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::OptionalApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::SetApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::CollectorsApi.adoc[leveloffset=+1]

Mon, 01 Jan 0001 00:00:00 +0000

Copy Of

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/ten/api/SetApi.java[tag=copyOf]

With Set.copyOf we can now create an immutable copy of a list.

Mon, 01 Jan 0001 00:00:00 +0000

var is not a keyword but a reserved type identifier. The type is inferred from the initializer.

See https://openjdk.java.net/projects/amber/LVTIstyle.html which discusses when var should be used and when best avoided.

var

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/ten/lang/LocalVariableTypeInference.java[tag=varTypeInference]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 10 release notes.

Unresolved directive in <stdin> - include::LocalVariableTypeInference.adoc[leveloffset=+1]

Mon, 01 Jan 0001 00:00:00 +0000

The new newFileSystem method allows to access the content of a file like a file system. Read more in the Java 13 Java API documentation.

New File System

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/thirteen/api/FileSystemsApi.java[tag=newFileSystem]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 13 release notes.

Unresolved directive in <stdin> - include::FileSystemsApi.adoc[leveloffset=+1]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java JVM. See the Java 13 release notes.

Class data sharing (CDS) allows class metadata to be shared across different JVM instances to reduce startup time. Java 13 is now delivering Dynamic CDS Archives with JEP 350 that simplifies the process of generating a shared archive when an application is exiting.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 13 release notes.

Java 13 is introducing the following language enhancements as developer preview.

JEP 354 is enhancing the switch expression introduced in {java12} by introducing the yield statement to return values from a switch expression.
JEP 355 introduces text blocks.A text block is a multi-line string literal that avoids the need for most escape sequences, automatically formats the string in a predictable way, and gives the developer control over format when desired.

Mon, 01 Jan 0001 00:00:00 +0000

Teeing

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twelve/api/CollectorsApi.java[tag=teeing]

With Collectors.teeing we can have two collectors process a stream. The results of both collectors are then processed by a merge function.

Mon, 01 Jan 0001 00:00:00 +0000

Mismatch

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twelve/api/FilesApi.java[tag=mismatch]

With Files.mismatch we can detect the first mismatching character while comparing two files.

Mon, 01 Jan 0001 00:00:00 +0000

Get Compact Number Instance

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twelve/api/NumberFormatApi.java[tag=getCompactNumberInstance]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 12 release notes.

Unresolved directive in <stdin> - include::CollectorsApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::FilesApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::StringApi.adoc[leveloffset=+1] Unresolved directive in <stdin> - include::NumberFormatApi.adoc[leveloffset=+1]

Mon, 01 Jan 0001 00:00:00 +0000

Indent

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twelve/api/StringApi.java[tag=indent]

With String::indent we can easily indent any string. With earlier Java versions we would have to use 3rd-party libraries such as Apache commons-lang or implement yourself..

Transform

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twelve/api/StringApi.java[tag=transform]

With String::transform we can easily transform any string.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java JVM. See the Java 12 release notes.

With JEP-341, now CDS archives are built during the JDK build. CDS is already on by default as of {java11}.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 20 release notes.

Java 20 is introducing the following API enhancements as developer preview or Incubator.

JEP 429 is introducing scoped values, which enable the sharing of immutable data within and across threads. They are preferred to thread-local variables, especially when using large numbers of virtual threads
JEP 436 is introducing virtual threads to the Java Platform. Virtual threads are lightweight threads that dramatically reduce the effort of writing, maintaining, and observing high-throughput concurrent applications.
JEP 437 is simplifying multithreaded programming by introducing an API for structured concurrency. Structured concurrency treats multiple tasks running in different threads as a single unit of work, thereby streamlining error handling and cancellation, improving reliability, and enhancing observability..

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 20 release notes. See Java Language Updates for Java SE 20.

Java 20 is introducing the following language enhancements as developer preview.

JEP 432 is continuing with Record Patterns as developer preview
JEP 433 is continuing with Pattern Matching for switch.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 25 release notes.

Java 25 is introducing the following finalized API enhancements.

JEP 506 is finalizing Scoped Values. Enable the sharing of immutable data within and across threads. They are preferred to thread-local variables, especially when using large numbers of virtual threads.
JEP 510 is introducing Key Derivation Function API. Provide an API for Key Derivation Functions (KDFs), which are cryptographic algorithms for deriving additional keys from a secret key or other high-entropy key material.

Mon, 01 Jan 0001 00:00:00 +0000

Before Java 25, ThreadLocal variables were used to share request context across method calls. ThreadLocal requires manual cleanup and has memory overhead with virtual threads.

Request Context With Thread Local

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyfive/api/ScopedValues.java[tag=requestContextWithThreadLocal]

Request Context With Scoped Value

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyfive/api/ScopedValues.java[tag=requestContextWithScopedValue]

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java Virtual Machine. See the Java 25 release notes.

Java 25 is introducing the following finalized JVM enhancements.

JEP 518 is introducing JFR Cooperative Sampling. Enhance Java Flight Recorder (JFR) with cooperative sampling capabilities, allowing applications to participate in profiling decisions and reduce overhead.
JEP 519 is introducing Compact Object Headers. Reduce the memory footprint of Java objects by implementing compact object headers, improving memory efficiency and performance.
JEP 520 is introducing JFR Method Timing & Tracing. Enhance Java Flight Recorder with improved method-level timing and tracing capabilities for better application performance analysis.
JEP 521 is introducing Generational Shenandoah. Improve application performance by extending Shenandoah to maintain separate generations for young and old objects, allowing more frequent collection of short-lived objects.

Mon, 01 Jan 0001 00:00:00 +0000

Before Java 25, constructor bodies were restricted - all statements had to appear after the explicit constructor invocation (super() or this()).

Constructor Before Java25

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyfive/lang/FlexibleConstructorBodies.java[tag=constructorBeforeJava25]

Constructor With Java25

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyfive/lang/FlexibleConstructorBodies.java[tag=constructorWithJava25]

Java 25 allows statements that don’t reference the instance being created to appear before the explicit constructor invocation, providing more flexibility.

Mon, 01 Jan 0001 00:00:00 +0000

Java 25 also allows instance main methods within classes, eliminating the need for static methods and making object-oriented concepts more natural for beginners.

Static Main Before Java25

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyfive/lang/InstanceMainMethods.java[tag=staticMainBeforeJava25]

Instance Main Method

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyfive/lang/InstanceMainMethods.java[tag=instanceMainMethod]

Mon, 01 Jan 0001 00:00:00 +0000

Module Import With Java25

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyfive/lang/ModuleImportDeclarations.java[tag=moduleImportWithJava25]

Java 25 introduces module import declarations that allow importing all exported packages from a module with a single statement using the import module syntax.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 25 release notes. See Java Language Updates for Java SE 25.

Java 25 is introducing the following finalized language enhancements.

JEP 511 is finalizing Module Import Declarations. Enhance the Java programming language with the ability to succinctly import all of the packages exported by a module. This simplifies the reuse of modular libraries, but does not require the importing code to be in a module itself.
JEP 512 is finalizing Compact Source Files and Instance Main Methods. Enhance the Java programming language so that students can write their first programs without needing to understand language features designed for large programs.
JEP 513 is finalizing Flexible Constructor Bodies. In constructors in the Java programming language, allow statements that do not reference the instance being created to appear before an explicit constructor invocation.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java platform and tooling. See the Java 25 release notes.

Java 25 is introducing the following platform and tooling enhancements.

JEP 503 is Remove the 32-bit x86 Port. Remove the 32-bit x86 port (linux-x86) from the JDK, continuing the modernization of supported platforms.
JEP 514 is introducing Ahead-of-Time Command-Line Ergonomics. Improve the usability of ahead-of-time compilation by enhancing command-line tools and their ergonomics for better developer experience.
JEP 515 is introducing Ahead-of-Time Method Profiling. Enable method-level profiling information to be collected and used during ahead-of-time compilation to improve application startup and performance.

Mon, 01 Jan 0001 00:00:00 +0000

Before Java 24, working with Java class files required third-party libraries like ASM or BCEL. The new Class-File API provides a standard way to parse, generate, and transform Java class files.

Parse Class File

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyfour/api/ClassFileApi.java[tag=parseClassFile]

Generate Class File

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 24 release notes.

Java 24 is introducing the following finalized API enhancements.

JEP 484 is finalizing the Class-File API. Provide a standard API for parsing, generating, and transforming Java class files. This API will replace the need for third-party libraries like ASM.
JEP 485 is finalizing Stream Gatherers. Enhance the Stream API to support custom intermediate operations. This will allow stream pipelines to transform data in ways that are not easily achievable with the existing built-in intermediate operations.
JEP 496 is introducing Quantum-Resistant Module-Lattice-Based Key Encapsulation Mechanism. Provide implementations of KEM based on the Module-Lattice-Based Key-Encapsulation Mechanism (ML-KEM) standard specified in FIPS 203.
JEP 497 is introducing Quantum-Resistant Module-Lattice-Based Digital Signature Algorithm. Provide implementations of the Module-Lattice-Based Digital Signature Algorithm (ML-DSA) standard specified in FIPS 204.

Mon, 01 Jan 0001 00:00:00 +0000

Before Java 24, creating sliding windows required complex collectors or external loops.

Sliding Window Before Java24

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyfour/api/StreamGatherers.java[tag=slidingWindowBeforeJava24]

Sliding Window With Java24

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyfour/api/StreamGatherers.java[tag=slidingWindowWithJava24]

Java 24 Stream Gatherers provide built-in sliding window operations as intermediate operations.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java Virtual Machine. See the Java 24 release notes.

Java 24 is introducing the following finalized JVM enhancements.

JEP 475 is introducing Late Barrier Expansion for G1. Improve G1 garbage collector performance by moving the expansion of GC barriers from the platform-independent optimization phase to the platform-dependent code generation phase.
JEP 490 is ZGC: Remove the Non-Generational Mode. Remove ZGC’s non-generational mode, retaining only the generational mode, which offers better application performance.
JEP 491 is introducing Synchronize Virtual Threads without Pinning. Enable virtual threads to synchronize without pinning the underlying platform thread by reimplementing object monitors to use a new locking scheme.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 24 release notes. See Java Language Updates for Java SE 24.

Java 24 is introducing the following language enhancements as developer preview.

JEP 488 is continuing with Primitive Types in Patterns, instanceof, and switch (Second Preview). Enhance pattern matching by allowing primitive type patterns in all pattern contexts, and extend instanceof and switch to work with all primitive types.
JEP 492 is continuing with Flexible Constructor Bodies (Third Preview). In constructors in the Java programming language, allow statements that do not reference the instance being created to appear before an explicit constructor invocation.
JEP 494 is continuing with Module Import Declarations (Second Preview). Enhance the Java programming language with the ability to succinctly import all of the packages exported by a module. This simplifies the reuse of modular libraries, but does not require the importing code to be in a module itself.
JEP 495 is continuing with Simple Source Files and Instance Main Methods (Fourth Preview). Enhance the Java programming language so that students can write their first programs without needing to understand language features designed for large programs.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java platform and tooling. See the Java 24 release notes.

Java 24 is introducing the following platform and tooling enhancements.

JEP 472 is Prepare to Restrict the Use of JNI. Prepare to restrict the use of JNI by issuing warnings when JNI is used by code on the class path. This prepares for a future release that will throw exceptions instead of issuing warnings.
JEP 479 is Remove the Windows 32-bit x86 Port. Remove the Windows 32-bit x86 port (windows-x86) from the JDK.
JEP 483 is introducing Ahead-of-Time Class Loading & Linking. Improve startup time and time to peak performance by enabling classes to be loaded and linked ahead of time.
JEP 486 is Permanently Disable the Security Manager. Permanently disable the Security Manager, which has been deprecated since Java 17 and marked for removal.
JEP 493 is introducing Linking Run-Time Images without JMODs. Enable jlink to create run-time images without requiring JMOD files to be present, provided that the packaged modules contain the same content.
JEP 498 is Warn upon Use of Memory-Access Methods in sun.misc.Unsafe. Issue warnings when memory-access methods in sun.misc.Unsafe are used. This prepares for their eventual removal or restriction.
JEP 501 is Deprecate the 32-bit x86 Port for Removal. Deprecate the 32-bit x86 port (linux-x86) with the intent to remove it in a future release.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 21 release notes.

Java 21 is introducing the following API/library enhancements.

JEP 444 Virtual threads are lightweight threads that dramatically reduce the effort of writing, maintaining, and observing high-throughput concurrent applications.
JEP 431 Sequenced Collections Introduce new interfaces to represent collections with a defined encounter order. Each such collection has a well-defined first element, second element, and so forth, up to the last element. It also provides uniform APIs for accessing its first and last elements, and for processing its elements in reverse order.

Mon, 01 Jan 0001 00:00:00 +0000

Sequenced Collection List Implementation

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyone/api/SequencedCollectionApi.java[tag=sequencedCollectionListImplementation]

Collection implementations with items in defined order hat a rather inconsistent API. Those collection types now implement SequencedCollection offering methods for accessing head and tail elements and reversing the ordering.

Set types that are maintaining a sequence have their own interface SequencedSet sub-type.

Mon, 01 Jan 0001 00:00:00 +0000

Like platform threads, a virtual thread is also an instance of java.lang.Thread class, but does not allocate a specific OS thread and consumes much less OS resources.

Executors

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyone/api/VirtualThreads.java[tag=executors]

For frameworks that are managing multi-threading it’s usually just a matter of the proper configuration to switch from platform threads to virtual threads. Spring Boot for example just requires spring.threads.virtual.enabled=true in the application configuration.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 21 release notes. See Java Language Updates for Java SE 21.

With Java 21 the following language enhancements are now generally available

JEP 440 is now releasing Record Patterns.
JEP 441 is now releasing Pattern Matching for switch.

Mon, 01 Jan 0001 00:00:00 +0000

Record Pattern Matching With Instance Of

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyone/lang/Record.java[tag=recordPatternMatchingWithInstanceOf]

Record Pattern Matching With Switch

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentyone/lang/Record.java[tag=recordPatternMatchingWithSwitch]

Record patterns with switch support many more additional features like when clauses. Read more on the Java 21 language document for Pattern Matching for switch Expressions and Statements.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 23 release notes.

Java 23 is introducing the following API enhancements as developer preview or Incubator.

JEP 466 is continuing with Class-File API, standard API for parsing, generating, and transforming Java class files
JEP 473 is continuing with Stream Gatherers. This will allow stream pipelines to transform data in ways that are not easily achievable with the existing built-in intermediate operations
JEP 480 is continuing with simplifying multithreaded programming by introducing an API for structured concurrency. Structured concurrency treats multiple tasks running in different threads as a single unit of work, thereby streamlining error handling and cancellation, improving reliability, and enhancing observability..
JEP 481 is continuing with scoped values, which enable the sharing of immutable data within and across threads. They are preferred to thread-local variables, especially when using large numbers of virtual threads
JEP 469 is continuing with Vector API, introduces an API to express vector computations that reliably compile at runtime to optimal vector instructions on supported CPU architectures, thus achieving performance superior to equivalent scalar computations.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 23 release notes. See Java Language Updates for Java SE 23.

Java 23 is introducing the following language enhancements as developer preview.

JEP 455 is starting with Primitive Types in Patterns, instanceof, and switch (Preview) as developer preview. Enhance pattern matching by allowing primitive type patterns in all pattern contexts, and extend instanceof and switch to work with all primitive types.
JEP 476 is starting with Module Import Declarations as developer preview. Enhance the Java programming language with the ability to succinctly import all of the packages exported by a module. This simplifies the reuse of modular libraries, but does not require the importing code to be in a module itself.
JEP 482 is continuing with Flexible Constructor Bodies as developer preview. In constructors in the Java programming language, allow statements that do not reference the instance being created to appear before an explicit constructor invocation.
JEP 477 is continuing with Implicitly Declared Classes and Instance Main Methods.

Mon, 01 Jan 0001 00:00:00 +0000

Before Java 23 HTML JavaDoc syntax is verbose and hard to read in source code.

Basic Formatting Before Java23

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentythree/tooling/MarkdownDocumentationComments.java[tag=basicFormattingBeforeJava23]

Basic Formatting With Java23

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentythree/tooling/MarkdownDocumentationComments.java[tag=basicFormattingWithJava23]

Java 23 Markdown JavaDoc is clean and intuitive to write.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java tooling. See the Java 23 release notes.

Java 23 is introducing the following tooling enhancements.

JEP 467 is adding the Markdown Documentation Comments. This enables JavaDoc documentation comments to be written in Markdown rather than solely in a mixture of HTML and JavaDoc @-tags.

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java API. See the Java 22 release notes.

Java 22 is introducing the following API enhancements as developer preview or Incubator.

JEP 446 is continuing with scoped values, which enable the sharing of immutable data within and across threads. They are preferred to thread-local variables, especially when using large numbers of virtual threads
JEP 457 is starting with a Class-File API to provide a standard API for parsing, generating, and transforming Java class files. This could eliminate the need for libraries like ASM.
JEP 453 is continuing with simplifying multithreaded programming by introducing an API for structured concurrency. Structured concurrency treats multiple tasks running in different threads as a single unit of work, thereby streamlining error handling and cancellation, improving reliability, and enhancing observability..
JEP 461 is starting Stream Gatherers. This will allow stream pipelines to transform data in ways that are not easily achievable with the existing built-in intermediate operations

Mon, 01 Jan 0001 00:00:00 +0000

The following describes selected improvements of the Java language. See the Java 22 release notes. See Java Language Updates for Java SE 22.

With Java 22 the following language enhancements are now generally available

JEP 456 is releasing Unnamed Patterns and Variables. Unnamed patterns, which match a record component without stating the component’s name or type, and unnamed variables, which can be initialized but not used. Both are denoted by an underscore character, _.

Mon, 01 Jan 0001 00:00:00 +0000

The Java language mandates to declare variables (names) even when they are not needed (used). Often we also find ourselves to declare variables just for the sake of having a consistent look.

Unnamed Variables

Unresolved directive in <stdin> - include::../../../../../../../../src/main/java/twentytwo/lang/UnnamedVariablesAndPatterns.java[tag=unnamedVariables]

Unnamed Variables For Consistent Code Style

Mon, 01 Jan 0001 00:00:00 +0000

Gradle Configuration Cache

Mon, 01 Jan 0001 00:00:00 +0000

Test results - Test Summary

Test Summary

119

tests

failures

ignored

1.652s

duration

100%

successful

Packages

Package	Tests	Duration	Success rate
eighteen.tooling	2	0.025s	100%
eleven.api	6	0.027s	100%
eleven.lang	4	0.015s	100%
fifteen.api	1	0.002s	100%
fifteen.lang	1	0.002s	100%
fourteen.api	2	0.035s	100%
fourteen.lang	3	0.011s	100%
nine.api	28	0.067s	100%
nine.lang	4	0.005s	100%
nineteen.api	7	0.029s	100%
sixteen.api	2	0.011s	100%
sixteen.lang	4	0.005s	100%
ten.api	7	0.010s	100%
ten.lang	1	0.002s	100%
thirteen.api	1	0.047s	100%
twelve.api	5	0.039s	100%
twentyfive.api	6	0.050s	100%
twentyfive.lang	6	0.010s	100%
twentyfour.api	11	0.066s	100%
twentyone.api	3	1.168s	100%
twentyone.lang	2	0.002s	100%
twentythree.tooling	10	0.016s	100%
twentytwo.lang	3	0.008s	100%

Classes

Class	Tests	Duration	Success rate
eighteen.tooling.JavaDocSnippetTag	2	0.025s	100%
eleven.api.CollectionApi	1	0.008s	100%
eleven.api.FilesApi	1	0.013s	100%
eleven.api.PredicateApi	1	0.001s	100%
eleven.api.StringApi	3	0.005s	100%
eleven.lang.LambdaLocalVariable	4	0.015s	100%
fifteen.api.CharSequenceApi	1	0.002s	100%
fifteen.lang.TextBlock	1	0.002s	100%
fourteen.api.AccountingCurrencyFormatSupport	1	0.033s	100%
fourteen.api.NullPointerExceptions	1	0.002s	100%
fourteen.lang.SwitchExpressions	3	0.011s	100%
nine.api.CollectorsApi	2	0.009s	100%
nine.api.ImmutableListFactory	4	0.006s	100%
nine.api.ImmutableMapEntryFactory	2	0.002s	100%
nine.api.ImmutableMapFactory	4	0.006s	100%
nine.api.ImmutableSetFactory	4	0.006s	100%
nine.api.MatcherApi	2	0.005s	100%
nine.api.ObjectsApi	2	0.005s	100%
nine.api.OptionalApi	3	0.006s	100%
nine.api.StreamApi	5	0.022s	100%
nine.lang.PrivateInterfaceMethod	2	0.003s	100%
nine.lang.TryWithResource	2	0.002s	100%
nineteen.api.CollectionApi	5	0.005s	100%
nineteen.api.DateTimeFormatterApi	2	0.024s	100%
sixteen.api.DayPeriodSupport	1	0.009s	100%
sixteen.api.StreamApi	1	0.002s	100%
sixteen.lang.PatternMatchingForInstanceof	1	0.001s	100%
sixteen.lang.Record	3	0.004s	100%
ten.api.CollectorsApi	3	0.007s	100%
ten.api.ListApi	1	0s	100%
ten.api.MapApi	1	0.001s	100%
ten.api.OptionalApi	1	0.001s	100%
ten.api.SetApi	1	0.001s	100%
ten.lang.LocalVariableTypeInference	1	0.002s	100%
thirteen.api.FileSystemsApi	1	0.047s	100%
twelve.api.CollectorsApi	1	0.006s	100%
twelve.api.FilesApi	1	0.002s	100%
twelve.api.NumberFormatApi	1	0.029s	100%
twelve.api.StringApi	2	0.002s	100%
twentyfive.api.ScopedValues	6	0.050s	100%
twentyfive.lang.FlexibleConstructorBodies	2	0.001s	100%
twentyfive.lang.InstanceMainMethods	3	0.009s	100%
twentyfive.lang.ModuleImportDeclarations	1	0s	100%
twentyfour.api.ClassFileApi	3	0.042s	100%
twentyfour.api.StreamGatherers	8	0.024s	100%
twentyone.api.SequencedCollectionApi	2	0.002s	100%
twentyone.api.VirtualThreads	1	1.166s	100%
twentyone.lang.Record	2	0.002s	100%
twentythree.tooling.MarkdownDocumentationComments	10	0.016s	100%
twentytwo.lang.UnnamedVariablesAndPatterns	3	0.008s	100%

Mon, 01 Jan 0001 00:00:00 +0000

Build presentation

Add the location of asciidoctor-revealjs to the PATH variable (export PATH=./:$PATH).

Export the following variables

Unresolved directive in <stdin> - include::.env[]

Run the following command

gw compileClasses && \
./.gitlab-ci.d/build-presentation.sh && \
./.gitlab-ci.d/publish-presentation.sh`

Mon, 01 Jan 0001 00:00:00 +0000

Unresolved directive in <stdin> - include::common.adoc[] Unresolved directive in <stdin> - include::icons.adoc[] Unresolved directive in <stdin> - include::java-version.adoc[]

Unresolved directive in <stdin> - include::content.adoc[]