Rosetta

Check out Rosetta. Its what we use at HubSpot. https://github.com/HubSpot/Rosetta Its by far the best Object <--> Sql layer I've ever used. You manage your objects in Java like you normally would and then Rosetta maps your objects to columns in your SQL DB using Jackson. This means you can write plain ole SQL for very clean simple code. When it comes time to get data out of the DB it again uses Jackson to map the results back to objects in Java. I was super skeptical at first, but it makes reading/writing data out of a SQL database super simple, while encouraging very simple explicit sql.

SQL is just one type of DB language we use, but yes we use JDBI with some extensions we've built (such as https://github.com/HubSpot/Rosetta and other non-opensource) for our SQL database of choice, MySQL. But we also use a number of other databases with native java clients, such as HBase and ElasticSearch.