Hi,
I have 10+ years JAVA experience but I have never worked with the TIKA library before. As you have hinted, this should be a straight forward task so I would be happy to take a look into it for you and find out what the problem is.
If you're able to provide your sample file, and what the desired outcome is I can try that out first. Any code I can then give to you to be integrated into your existing project.
If you'd like to discuss further, please message.
Kind regards,
Chris