Do you see jakarta POI library a well established because it's not clear what is the status of the project now.
It's true that the DOC part of POI is less developed than the XLS part, but there has been some progress in the 3.0 alpha build. If it does what you need done, great, if it doesn't then chances are the missing feature won't be coming soon.
Is it worth trying in my project in which users will submit MS docs to me and I need to provide them with an interface to view those documents in the explorer as HTML.
As mentioned before, POI can extract text from DOC files. If that's sufficient for your purposes I don't see why you wouldn't give it a try.