How Java and Rust Work Together

Rust is a system-level language that provides fine-grained control over memory management, making it a popular choice for performance-critical applications. Java, on the other hand, excels in providing portability and high-level abstractions. By using the FFM API in Java 22, developers can leverage Rust’s performance and memory safety in Java applications.

It provides access to classes such as SymbolLookup, FunctionDescriptor, Linker, MethodHandle, Arena, and MemorySegment, which enable Java to call foreign functions and manage memory in more effective ways. On Rust's end, functions exposed to Java must adhere to the C ABI, ensuring compatibility between the two languages. The manual will explore how to allocate, manage, and release memory safely between Java and Rust, ensuring optimal performance and avoiding memory leaks or undefined behavior.