How Rust and Java Communicate

Java and Rust communicate through dynamic linking, where Rust compiles into a shared library file (e.g., .dll on Windows, .so on Linux, .dylib on macOS). Java loads this library and can interact with its functions. At a high level, the process looks like this:

• Rust: Write Rust functions, export them with #[no_mangle] and extern "C", and compile them into a shared library.
• Java: Use the Java FFM API to load the shared library, find the Rust functions, and invoke them.

The next sections will go step by step through both the Rust and Java setups.