Java Bytecode Descriptor Parser for Rust

Introduction

Effortlessly parse and manipulate Java bytecode descriptors in Rust. This crate provides a lightweight, efficient, and easy-to-use solution for working with Java class, field, and method descriptors. To use it, add the following lines to your Cargo.toml file:

[dependencies]
jdescriptor = "0.2.0"

Why Use This Crate?

✅ Parse Java Method Signatures – Extract return types, parameters, and more from JVM bytecode descriptors.
✅ Ultra-Lightweight – Zero dependencies and minimal runtime overhead.
✅ Rust & Java Interoperability – Perfect for Rust tools interacting with Java class files.
✅ Beyond Classfiles – Useful for RPC, static analysis, IDE plugins, serialization, and more!
✅ Optimized for Performance – Designed to handle large-scale descriptor processing efficiently.

For more details about Java bytecode descriptors, check out the relevant sections in the Java Virtual Machine Specification (JVMS):

• Field Descriptors: Section 4.3.2
• Method Descriptors: Section 4.3.3

Usage

Dealing with Type Descriptors

let parsed: TypeDescriptor = "[[Ljava/lang/String;".parse().unwrap();
println!("Rust representation: {:?}", parsed); // Array(Object("java/lang/String"), 2)
println!("Java representation: {}", parsed); // [[Ljava/lang/String;

Dealing with Method Descriptors

let parsed: MethodDescriptor = "(FIB)S".parse().unwrap();
println!("Rust structure: {:?}", parsed); // MethodDescriptor { parameter_types: [Float, Integer, Byte], return_type: Short }
println!("Java representation: {}", parsed); // (FIB)S

Use Cases

• Java Classfile Parsing – Helper for parsing .class files and analyze type and method signatures.
• Interoperability – Bridge Rust and Java, ensuring type correctness in JNI/FFI calls.
• Code Generation – Generate Java bindings, stubs, and DSLs with validated signatures.
• Static Analysis – Build security tools that detect unsafe Java method patterns.
• IDE Plugins & Developer Tools – Provide type hints and method signature insights.

Contributing

Contributions are welcome! Feel free to open an issue or submit a pull request.

License

This project is licensed under the MIT License – see the LICENSE file for details.