The FieldAnalysisRequestHandler provides the analysis functionality of the web admin page as a service. This handler accepts a filetype/fieldname parameter and a value and as a response returns a breakdown of the analysis process. It is also possible to send a query value which will use the configured query analyzer as well as a showmatch parameter which will then mark every matched token as a match.
If this handler is added to the code base, I also recommend to rename the current AnalysisRequestHandler to DocumentAnalysisRequestHandler and have them both inherit from one AnalysisRequestHandlerBase class which provides the common functionality of the analysis breakdown and its translation to named lists. This will also enhance the current AnalysisRequestHandler which right now is fairly simplistic.