Morphia — MongoDB Object Document Mapping for the JVM.

Bidirectional mapping to and from the database

Transparently map your Java entities to MongoDB documents and back.

Extensible Type Conversion

Easily add support for custom types

Robust Query and Update APIs
Full Aggregation Support

Use MongoDB’s aggregation framework with your application’s Java classes.

Annotation driven indexing
Geospatial Queries

Critter — Type safe criteria-builder for use with Morphia-based projects.

Build time query generated helpers

Check your query definitions at build time

Curated query and update operators

Only operations that make sense for the field’s type are exposed