如何在NoSQL世界中实现数据库抽象/独立性

We are looking at using MongoDB as our database in our Java Server-side application. In my earlier project we were using Hibernate to abstract the underlying SQL database, so that we could switch from MySQL to Postgres (for example) without changing application code. (this was a + that Hibernate gave us apart from the usual ORM feature). We are looking at using MongoDB as our database