We are building an ecommerce application. We are using JAVA stack with Hibernate and Spring Framework. As with all ecommerce application, we need to build search capability
It sound like you need to read up on the pros and cons of each of these. There is extensive documentation available.
If you wanted my opinion I would say that it makes sense to use Hibernate Search with Hibernate. The updating of search indexes occurs when hibernate performs database operations and only when a database transaction is committed.