Merge pull request #77 from Pi4J/feature/java21

Prepare content for bump to Java 21

Author: FDelporte

config.toml

@@ -124,7 +124,7 @@ weight = 20
 [[menu.shortcuts]]
 name = "<i class='fab more-tag fa-github'></i> Pi4J V2 Discussions"
 identifier = "discussions"
-url = "https://github.com/Pi4J/pi4j-v2/discussions"
+url = "https://github.com/Pi4J/pi4j/discussions"
 weight = 30
 
 [[menu.shortcuts]]

content/_index.md

@@ -4,6 +4,10 @@ title: Welcome to Pi4J
 
 ## Welcome to Pi4J
 
+{{% notice warning %}}
+Pi4J is moving to Java version 21! Please [read this blog post for more info](/blog/2025/20250205-welcome-java-21/).
+{{% /notice %}}
+
 **Latest release: V2.8.0 (2025-01-28, see [Release Notes](/about/release-notes/)).**
 
 This project is intended to provide **a friendly object-oriented I/O API and implementation libraries for Java Programmers** to access the **full I/O capabilities of the Raspberry Pi platform**. This project abstracts the low-level native integration and interrupt monitoring to enable Java programmers to **focus on implementing their application business logic**.
@@ -36,17 +40,9 @@ capabilities of embedded platforms such as the Raspberry Pi.
 
 The Pi4j project has evolved in all these years as the whole Java eco-system and Raspberry Pi systems have been evolving.
 
-This resulted in two main versions.
-
-#### Version 1
-
-The original library which started in 2012 and got a last release in 2021. Up till **version 1.3 the library targets Java 8**, while **version 1.4 relies on Java 11**. 
-
-More info is provided on ["Previous versions (V.1)"](/about/previous-version-v1/).
-
-#### Version 2
+This resulted in the following main versions:
 
-As of Version 2.0, Pi4J **no longer includes support for peripheral devices and
-add-on chipsets/boards** as part of the core project. A new plugin model has been introduced in version 2.0 that helps to enable third-party development and support third-party add-ons which can be developed and maintained independently of the core Pi4J project.
+* [V1.X.X](/about/info-v1): Deprecated, based on Java 8, later Java 11.
+* [V2.X.X](/about/info-v2): Completely reworked code base, based on Java 11.
+* [V3.X.X](/about/info-v3): Based on latest V2 and Java 21.
 
-More info is provided on ["What's New (V.2)"](/about/new-in-v2/).

content/about/_index.md

@@ -5,8 +5,8 @@ weight: 10
 
 ## Project Status/Summary
 
-Pi4J V.2 is a complete re-write and **does not maintain API compatibility** with previous 
-versions.  It is not intended to be a drop-in replacement for previous versions of Pi4J.  Pi4J V.2 is 
+Pi4J V2+ is a complete re-write and **does not maintain API compatibility** with previous 
+versions.  It is not intended to be a drop-in replacement for previous versions of Pi4J.  Pi4J V2+ is 
 a completely new **design bringing modern conventions, development practices, extensibility support 
 and simplified integration experience** for Pi4J users.
 

content/about/previous-version-v1.md content/about/info-v1.mdcontent/about/previous-version-v1.md renamed to content/about/info-v1.md

@@ -1,8 +1,12 @@
 ---
-title: 'Previous versions (V.1)'
+title: 'Info about V1'
 weight: 20
 ---
 
+The original library which started in 2012 and got a last release in 2021. Up till **version 1.3.0 the library targets Java 8**, while **version 1.4.0 relies on Java 11**.
+
+[The sources of V1 can be found in the read-only GitHub repository `pi4j/pi4j-v1`](https://github.com/Pi4J/pi4j-v1).
+
 ## Documentation of the 1.X versions
 
 ### Pi4J Version 1.4
@@ -15,7 +19,7 @@ weight: 20
 * Removed pi4j-device and pi4j-gpio-extension library
 * Removed platform support for Odroid, BananaPi, BPi, NanoPi, OrangePi
 * Various improvements and bug fixes listed here: [GitHub Issues (v1.4)](https://github.com/Pi4J/pi4j-v1/milestone/9?closed=1)
-* Not using Java-modules yet, this will be part of the V.2
+* Not using Java-modules yet, this will be part of the V2
 * [Documentation website V1.4](/1.4/index.html)
 
 ### Pi4J Version 1.3

content/about/new-in-v2.md content/about/info-v2.mdcontent/about/new-in-v2.md renamed to content/about/info-v2.md

@@ -1,8 +1,12 @@
 ---
-title: 'What''s New (V.2)'
-weight: 30
+title: 'What''s New in V2'
+weight: 21
 ---
 
+As of versions 2.X.X, Pi4J **no longer includes support for peripheral devices and add-on chipsets/boards** as part of the core project. A new plugin model has been introduced in version 2.0 that helps to enable third-party development and support third-party add-ons which can be developed and maintained independently of the core Pi4J project. **V2-versions of Pi4J require Java 11** or higher.
+
+[The sources of V2+ can be found in the GitHub repository `pi4j/pi4j`](https://github.com/Pi4J/pi4j).
+
 ## What's New in 2.0?
 
 Pi4J version 2.0 brings with it many new features, and an entirely new architecture that focuses on 
@@ -33,7 +37,7 @@ Pi4J version 2.0 will no longer be based on WiringPi and has moved to using the
 With this move, we will also support the remote I/O features (via TCP socket) offered by the PIGPIO daemon 
 ([http://abyz.me.uk/rpi/pigpio/pigpiod.html](http://abyz.me.uk/rpi/pigpio/pigpiod.html)).
 
-## What are the differences compared to V.1?
+## What are the differences compared to V1?
 
 Starting with the Pi4J 2.0 builds, the Pi4J project is prioritizing focus on providing Java programs access, 
 control and communication with the core I/O capabilities of the Raspberry Pi platform. Earlier versions of Pi4J were 
@@ -50,12 +54,12 @@ The following features have been removed from the Pi4J library:
 
 ## Sources
 
-The Pi4J V.2 source code is available in this GitHub repository: [Pi4J V.2 GitHub Repository](https://github.com/Pi4J/pi4j-v2)
+The Pi4J V2+ source code is available in this GitHub repository: [`pi4j/pi4j` GitHub Repository](https://github.com/Pi4J/pi4j)
 
 ```shell
-git clone https://github.com/Pi4J/pi4j-v2
+git clone https://github.com/Pi4J/pi4j
 ```
 
-Pi4J V.2 had the first release in August 2021. Rework from V.1 to V.2 took quit some time and will never be finished, but
+Pi4J V2 had the first release in August 2021. Rework from V1 to V2 took quit some time and will never be finished, but
 we are confident this is a great library to develop Java application on the Raspberry Pi. Any remarks and contributions
-are welcome as either bug reports or discussions in the [GitHub repository](https://github.com/Pi4J/pi4j-v2).
+are welcome as either bug reports or discussions in the [GitHub repository](https://github.com/Pi4J/pi4j).

content/about/info-v3.md

@@ -0,0 +1,42 @@
+---
+title: 'What''s New in V3'
+weight: 22
+---
+
+Versions 3.0.0 is based on 2.8.0 (released in January 2025), but bumps the **Java version to 21** or newer! We [asked our users](https://github.com/Pi4J/pi4j/discussions/409) which minimal Java version we should use, but there was no one clear answer, as expected ;-)
+
+The current/latest Long Term Support (LTS) version of Java is version 21. So it makes sense to jump forward from 11 to 21. This will also prepare us for a the next LTS, which will be Java 25 in September 2025. Bumping to the latest LTS makes it possible to make use of many newer Java language and runtime improvements, simplify some of the code, etc.
+
+We would like to move to Java 22 as this would allow us to easier call C code to interact with the GPIOs, thanks to [JEP 454: Foreign Function & Memory API](https://openjdk.org/jeps/454). Unfortanelty, 22 is not a LTS, so it would force us to bump the version every six months with each new release, up till 25.
+
+[The sources of V3 can be found in the GitHub repository `pi4j/pi4j`](https://github.com/Pi4J/pi4j).
+
+## What's New in 3.0?
+
+Pi4J version 3.0.0 is a continuation of 2.8.0, but bumps the minimal Java version to 21.
+
+## Sources
+
+The Pi4J V3 source code is available in this GitHub repository: [`pi4j/pi4j` GitHub Repository](https://github.com/Pi4J/pi4j)
+
+```shell
+git clone https://github.com/Pi4J/pi4j
+```
+
+Pi4J V3 is not yet released, but can already use version `3.0.0-SNAPSHOT` for testing if you add the snapshot Maven repository to your pom-file.
+
+```xml
+<repositories>
+    <repository>
+        <id>oss-snapshots-repo</id>
+        <name>Sonatype OSS Maven Repository</name>
+        <url>https://oss.sonatype.org/content/groups/public</url>
+        <releases>
+            <enabled>false</enabled>
+        </releases>
+        <snapshots>
+            <enabled>true</enabled>
+        </snapshots>
+    </repository>
+</repositories>
+```

content/about/license.md

@@ -7,7 +7,7 @@ The Pi4J Version 2.0 project is distributed and licensed under the **Apache Lice
 (_A business-friendly OSS license_).
 
 * [apache.org/licenses/LICENSE-2.0](https://www.apache.org/licenses/LICENSE-2.0)
-* [github.com/Pi4J/pi4j-v2/blob/master/LICENSE.txt](https://github.com/Pi4J/pi4j-v2/blob/master/LICENSE.txt)
+* [github.com/Pi4J/pi4j/blob/master/LICENSE.txt](https://github.com/Pi4J/pi4j/blob/master/LICENSE.txt)
 
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