I know there is hibernate-search module. But hibernate-search is no relationship with main database. Sometimes main database queries needs fulltext search.

Popular database vendors supports fulltext index, fulltext search.
MySQL http://dev.mysql.com/doc/refman/5.7/en/fulltext-search.html
PostGreSQL https://www.postgresql.org/docs/9.5/static/textsearch-tables.html
Oracle http://stackoverflow.com/a/7440224/976115