Hi, buddies. Thanks for your information on the grammar.
I'm not an expert on parser, I just translate some MediaWiki PHP code into Java. I did not take a fully test on the parser, but it seems to work normally on several articles I copy from Wikipedia. Now only a subset of the MediaWiki Markup is supported, including heading, horizontal rule, internal links, list, quotes and tables. The parser might be very buggy now.
I think a 100% complete compatibility with Mediawiki is very difficult, and in fact dose not make sense. If only a subset of the grammar is supported, it still would be usable and useful in most cases.
According to the interoperability, I am using the Mwapi from MwJed, and it works very well.