What is Pi4J

See https://www.pi4j.com/1.2/index.html

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.

As I was learning Spring Boot myself, I thought the easiest way to learn was trying to build an example and write about it. So here we go… :-)

While trying out what Pi4J can do, I found it could easily be extended with a JavaFX application to provide info about the headers on a Pi board. This could later be extended to a remote/local (touch) User Interface using the REST interface from this post.

As my daily work mainly is Java and back-end stuff on “real servers”, I set myself for 2019 as a personal goal to experiment with Java 11 on a Raspberry PI.

What we will do

Based on the previous blog posts

• we can install and run Java 11
• we have a minimal JavaFX 11 application which runs fine on a PI

So there is one “small” step remaining: build something which actually does something on the PI, talking to the GPIO’s and show what’s happening.
Spoiler alert: this is what’s is going to look like:

In part 2 of this blog series Java 11 was successfully installed on a PI.

And in part 4 a running Java FX jar was generated on a PC.

I prefer a Java app above a web app, because starting a new “modern” web development requires you to pull a bunch of dependencies and a lot of files before you can start. While Java just needs the JDK and one Java file, even on a Raspberry PI (as described in PiJava - Part 2).

What is JavaFX?

From the Oracle site: “JavaFX is a set of graphics and media packages that enables developers to design, create, test, debug, and deploy rich client applications that operate consistently across diverse platforms.”

After my first (and failed) attempt to get Java 11 running on an old Raspberry PI, I bought a brand new 3 Model B+ version.

One of my goals for 2019 is experimenting with the latest Java and JavaFX versions on a Raspberry PI. After my experiments with the Python Pong game I was not very happy with the GUI I could build with Python and definitely wanted to try something similar, but with JavaFX which I like much more.