jep + uv

The goal of this project is to serve as an example of how one could integrate jep with uv, to provide a Java -> Python integration that is simple to use for developers and at the same time doesn't require manual setup by users.

One of the challenges I have faced in the past when using jep, when using it to build jars that are integrated into larger Java applications, those applications may not be aware of a Python dependency, and ultimately adding jep would force the end-user to install the correct Python version for usage with jep, which is both cumbersome and error-prone over time (as a Python update may break the jep usage.

So the main approach here is to use uv to either detect or install a fitting Python version for usage with jep. Additionally, the Python package we want to embed in the jar has its dependencies manged by uv, and the venv created by venv install.

Goals

• Provide a seamless end-user experience by not requiring any manual setup by the end-user
• Provide a good developer experience by:
  • providing a simple way to use a Python package with dependencies (including native dependencies)
  • providing a consistent Python environment with a predictable Python version
• Provide an example project, that can be adjusted in individual parts to support similar use-cases
• Should work both with JRE8 and JRE20 (both a old an new Java version, that one will commonly find in older Java projects)

Non-goals

• Provide a ready-to-use library that can be plugged into other Java projects (I don't have the maintenance capacity to do that)
• Runtime installation of the package dependencies
  • dependencies are bundled into the .jar file at build-time, and extracted at runtime
  • trying to install the dependencies at runtime would become very difficult with native dependencies, as build tools would need to be present on the end-users machine
• Cross-compilation/multi-platform support (e.g. building a windows-compatible .jar on a linux machine)
  • Again due to native dependencies, this could become very difficult to achieve