Add sources and javadocs

Jochen Kressinrequested to merge
add_sources_javadoc into main

Merge request reports

floragunn GmbH - Tempelhofer Ufer 16 - 10963 Berlin - Germany- Managing Directors: Claudia Kressin, Jochen Kressin - Amtsgericht Charlottenburg HRB 147010 - VAT-ID: DE287373363