JASTG: Java AST structural graph—A tool for reproducible extraction of structural dependency graphs from Java systems

JASTG (Java Abstract Syntax Tree Structural Graph) is an open-source tool for deterministic extraction of structural dependency graphs from Java systems using AST-based static analysis. It identifies explicit typed dependencies, including inheritance, interface implementation, field types, method parameters and instantiations, and exports weighted graphs in GraphML format. Object-oriented metrics such as LCOM4, CBO, RFC, NOM and NOA are computed per node. The tool operates directly on source code without build system integration, ensuring environment-independent and reproducible results. A versioned benchmark dataset comprising graphs and metrics from 21 Java systems is publicly available on Zenodo, enabling independent validation and reuse in structural modularity research.