This will download the OpenAPI-specification, generate a client and compile the sources
./gradlew build
To execute the sample application, you will need to set environment variables containing the GTI-credentials.
GTI_USER=<user> GTI_HMAC_SECRET=<hmac secret> ./gradlew run
You can request GTI credentials at https://www.hvv.de/de/fahrplaene/abruf-fahrplaninfos/datenabruf