A pure Java implementation of the Protocol Buffers compiler (protoc).

This project aims to provide a dependency-free, pure Java version of the Protocol Buffers compiler. It is designed to be a faithful port of the original C++ protoc implementation, maintaining the same internal structure and logic to ensure bit-wise parity in generated code.

This allows Java developers to integrate Protocol Buffers compilation directly into their build process without requiring a local installation of the C++ protoc binary.

The project is organized into three main modules:

• protobuf-java-compiler: The core compiler implementation. This code is a direct port of the C++ source files found in the google/protobuf repository. It targets the package com.rubberjam.protobuf.another.compiler.
• protobuf-maven-plugin: A Maven plugin that wraps the protobuf-java-compiler, allowing users to compile .proto files as part of their Maven build lifecycle.
• protoc-maven-plugin: A utility plugin that wraps the native protoc executable. This is primarily used within this project's build process to generate "gold master" baselines for testing and verification purposes.

The project is currently a work in progress. The porting process follows a strict file-by-file conversion strategy to ensure accuracy and maintainability.

Please refer to CONVERSION_ORDER.md for a detailed list of converted files and the current status of the project.

To use the pure Java compiler in your Maven project, add the protobuf-maven-plugin to your pom.xml.

<plugin>
    <groupId>com.rubberjam.protobuf</groupId>
    <artifactId>protobuf-maven-plugin</artifactId>
    <version>1.0-SNAPSHOT</version>
    <executions>
        <execution>
            <goals>
                <goal>compile</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <!-- Optional: Defaults to src/main/proto -->
        <sourceDirectory>src/main/proto</sourceDirectory>
        <!-- Optional: Defaults to target/generated-sources/protobuf -->
        <outputDirectory>target/generated-sources/protobuf</outputDirectory>
    </configuration>
</plugin>

The plugin attaches to the generate-sources phase by default.

For developers contributing to this project:

• Follow the CONVERSION_ORDER.md to pick up tasks.
• See PROTOC.md for detailed notes on the internal architecture and porting guidelines.