java-ffi-example

Example use of FFI for Java >= 22.

Print the contents of results.txt using fopen, fgets and fclose from the system libc.

Building and running

Prerequisites

Set the JAVA_HOME environment variable to the Java installation path (needs to be Java version 22 or later).

For example, for macOS + homebrew + zsh: export JAVA_HOME=/opt/homebrew/Cellar/openjdk/22.0.1/.

make is also required.

Building

make

Running

make run

The contents of results.txt will then be printed, using fopen, fgets and fclose from the system libc.

References

Inspired by:

• https://ifesunmola.com/how-to-use-the-foreign-function-api-in-java-22-to-call-c-libraries/

Which in turn was inspired by:

• https://docs.oracle.com/en/java/javase/21/core/foreign-function-and-memory-api.html
• https://github.com/openjdk/jextract
• https://jdk.java.net/jextract/
• (YouTube) Foreign Function & Memory API - A (Quick) Peek Under the Hood
• (YouTube) Java 22 Launch Stream with Jorn Vernee and Per Ake Minborg
• https://news.ycombinator.com/item?id=34580907#34586552

General info

• Version: 1.0.0
• License: CC0