These days, the repository access is generally done via a web interface such as WebDAV. In fact, Subversion itself uses WebDAV for its web server interfacing.
There are tons of web-based document management systems out there. In fact, the Wikipedia is a web-based document management system which is based on freely-available open-source code. Wikis are very popular as knowledge bases and repositories. Many of them even incorporate version control so you can track a document's history.
And speaking of version control, there's often a certain amount of document management in modern version control systems. GitHub-style repositories often have hooks in their web interfaces such that basic markup can be done to a file and the web interface will present it formatted. It has become somewhat of a convention that there will be a README.md file in a git-based project that outlines what the project is about and (often) how to set it up and use it.
Be aware that using svnkit might entail having to obtain a license, depending on how you use it. You could access the svn libraries via something like JNI or JNA, but it seems you want Java only.
Have you considered proper document management systems, for which which there are several open source Java solutions? Apache Jackrabbit comes to mind as a JCR-compatible implementation, but there are others.
Don't you have an IDE?
You will need to cast to read them.
I have no idea what these lines are supposed to be doing: