TikaSearchProvider extends LuceneSearchProvider by bringing in Apache Tika to index all kind of attachments. As this Search Provider carries on a lot of dependencies (+55MB), it is not included by default on the main distributables (war, portables, etc).
To enable it you must add the jspwiki-tika-searchprovider jar on the war's WEB-INF/lib and add the following property to your jspwiki[-custom].properties file:
jspwiki.searchProvider = org.apache.wiki.search.tika.TikaSearchProvider
You can see an integration sample at https://github.com/juanpablo-santos/jspwiki-tika-searchprovider.git
associated JIRA issue: JSPWIKI-469