☕️🦀 java-oxide-gen

Easily generate type-safe bindings for calling Java APIs from Rust.

Features

• Generates fully safe Rust bindings to call Java APIs.
• Supports both static and nonstatic methods and fields.
• Constant fields (static final) are converted to Rust constants.
• Allows implementing Java interfaces or subclassing Java classes using generated Java proxies. Useful for callback/listener APIs. It generates:
  • a Rust trait matching the Java interface/class for you to implement
  • a proxy Java class where all methods call into Rust
  • Rust glue to receive and forward calls to the Rust trait
• Flexible configuration based on glob rules matching Java classes. All matching rules are merged.
• (NOT IMPLEMENTED YET) The ability to use pre-generated binding sources instead of having to rebind whole ABIs
• (NOT IMPLEMENTED YET) Generate stubbed JARs that you can include in your source code without issues (Always read the applicable licenses first, though)
• (NOT FULLY WRITTEN YET) Actual documentation on how to generate bindings

Differences vs java-spaghetti-gen (& jni-bindgen)

This project started out as a fork of java-spaghetti-gen, which is originally a fork jni-bindgen.

java-spaghetti-gen took the route of generating "mini-bindings", that are tailored specifically to your project, and can be embeded within your crate. This design, however, is not suited for large-scale bindings that are intended to be used as/in libraries. java-oxide partially goes back to the design of jni-bindgen, it generates crates with bindings for a whole java API (or multiple).

A list of differences from java-spaghetti-gen are:

• Configuration using TOML instead of YAML, to better fit in with the rest of the rust ecosystem.
• Generated code uses absolute paths (crate::...) instead of relative paths (super::...), because relative path chains can be confusing to read.
• (NOT IMPLEMENTED YET) Code is generated as multiple files following the package layout of the source JARs.
• (NOT IMPLEMENTED YET) Generated code does use some macros, cause it's easier to read that way (at least to me).
• EVEN MORE modernized rust and updated dependencies. java-spaghetti is stale, and slightly broken on newer rust versions.
• (NOT IMPLEMENTED YET) The ability to use pre-generated binding sources instead of having to rebind whole ABIs
• Better logging and error reporting

A list of differences from jni-bindgen are listed in java-spaghetti-gen's README.

TODO

• Switch back to a .toml configuration format
• Allow Glob Paths as inputs
• Add external pre-generated binding sources
• Fix code gen issues
  • Use absolute paths (crate::...)
  • Use SOME macros to improve readability
  • "Correctly" format generated code
  • Report to user what missing classes are causing incomplete code generations
• Use ristretto_classfile instead of cafebabe
• Implement stub generation
• Actually do documentation

License

Licensed under the MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)