hapifhir/hapi-fhir ? reverse-engineered prompt

Build me the HAPI FHIR project so I can work with HL7 FHIR data in Java.

I want a reusable library and server setup that lets me create FHIR clients, build a FHIR server, validate resources, and handle common healthcare workflows like search, storage, subscriptions, and terminology checks. If it makes sense, include a simple demo or sample app showing how to create, read, update, and search patient records.

Please keep it usable across the common FHIR versions this project supports, and make sure the pieces are organized so I can use just the client side, just the server side, or the full stack. If you need to, look up the current docs online for any setup details or best practices.

I’m mainly looking for something I can run locally, test easily, and extend without having to understand every internal module first.