Laserfiche/lf-repository-api-client-java ? reverse-engineered prompt

Build me a Java library for working with the Laserfiche Repository API.

I want it to make it easy for someone to connect to a Laserfiche repository, sign in securely with OAuth 2.0, and call the repository APIs to do common things like browse folders, upload and download files, update templates and field values, and manage repository content. It should be set up as a clean Maven project, work with Java 8, and include support for both the older API and the newer one if that fits the project structure. Please also make sure the code is easy to use from another Java app, with clear examples, sensible defaults, and basic tests so I can see how it’s meant to work.

If you need to check current API details or packaging conventions, look them up online and keep the implementation aligned with the official Laserfiche docs.