JBlogEditor is supposedly a blog posting program for Java. And this is probably true. It starts, it asks for a blog to post to, it connects to it and download it's categories and asks you if you want to write a new post.
The problem with JBlogEditor as of version is that you can't post blogs. As of version 0.6 it just throws you a obscure error message and refuses to open the editor...
It probably is a blog client, and you might even get it to work for you. Perhaps. Perhaps the upcoming v0.7's editor does more than show an error. Who knows. But as of now JBlogEditor isn't really a usable alternative.