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.
The Pi4J Project was started in 2012, the same year the Raspberry Pi was introduced as a tool to provide Java developers a simple and familiar object-oriented interface library to access the low-level I/O capabilities of the Raspberry Pi including GPIO, I2C, SPI, PWM and Serial communications.
The Pi4J Project’s mission is to provide a rich and powerful, yet simple to use, Java-friendly API library enabling programmatic access to the low-level hardware I/O 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.
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)".
As of Version 2.0, Pi4J will no longer include 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 should help enable third-party development and support third-party add-ons which may be developed and maintained independently of the core Pi4J project.
Read more on “What’s New (V.2)".