stephen-riley/JavaPlantUmlGenerator

A command line program to generate PlantUML class diagrams from Java files.

JavaPlantUmlGenerator

A command line program to generate PlantUML class diagrams from Java files.

Written in C#; uses ANTLR 4 and its reference Java grammar to parse Java files.

Usage

1. Install .NET 5.0 SDK
2. git clone https://github.com/stephen-riley/JavaPlantUmlGenerator.git
3. cd JavaPlantUmlGenerator
4. dotnet run -- /path/to/*.java > diagram.puml

About

This is a very simple project that illustrates how to use a pre-existing grammar and language tools to construct a simple "transpiler"; in this case, from Java source code to PlantUML class diagrams.

The structure of the program is quite simple. ANTLR is used to generate a lexer, parser, and Visitor base class from a Java 9 grammar. The ClassExtractor class subclasses the Visitor base and overrides a minimal number of methods to intercept certain points of the grammar; namely:

• normalClassDeclaration
• normalInterfaceDeclaration
• enumDeclaration
• methodHeader
• fieldDeclaration

These overrides record information such as class names and members, which are then emitted in .puml syntax by the Emit() method.