Need help with uploading files via API (Java)

Hey there!

I want to upload files to my cloud & create a share link with a java application and dont know how to do so. There are some docs for Javascript & python api wrappers but nothing for Java. Could only find a pretty much undocumented api wrapper here:

If someone can help me with that I´d really appreciate it. Using nextcloud 21.0.3 with apache2 running on a raspbian OS and the file upload would be from the same system as well. so technically I could just move it into the folder & run a sync. Then I still would need a way to create a share link tho.