Logstash in reading files/ documents

I would like to know if there are any ways that a logstash configuration file can read through different documents, i.e. docx, pdf, excels, and store them into elasticsearch.

Great thanks in advance.

I don't believe there are any stock plugins for this in Logstash. The Mapper Attachments plugin for ES might be of interest to you.

Then how about reading data from oracle database, is it possible for logstash to do that?

Look at the jdbc input.

Thanks, it helps the database part.