| Interface | Description |
|---|---|
| DataAccessObject |
Interface for accessing data in LensKit.
|
| Query<E extends Entity> |
Fluent interface for DAO queries.
|
| Class | Description |
|---|---|
| AbstractDataAccessObject |
Helper class to make it easier to create DAOs.
|
| EntityCollectionDAO |
A DAO backed by one or more collections of entities.
|
| EntityCollectionDAOBuilder |
Builder for entity collection DAOs.
|
| EntityQuery<E extends Entity> |
Representation of a query.
|
| EntityQueryBuilder |
Data query builder exposing a fluent interface.
|
| GroupedQuery<E extends Entity> |
Grouped query interface.
|
| SortKey |
A sort key describing a sort operation.
|
| Enum | Description |
|---|---|
| SortOrder |
| Exception | Description |
|---|---|
| DataAccessException |
An error occurred during data access.
|
| UnsupportedQueryException |
Exception thrown when a query cannot be supported.
|
LensKit data access objects.
LensKit uses Data Access Objects to obtain access to rating data. These objects allow LensKit to query for users, items, ratings, etc. The master DAO interface is defined by DataAccessObject. This interface can be reimplemented against other query APIs such as SQL databases, MongoDB, etc. LensKit provides basic implementations against static files and in-memory collections.
LensKit also uses intermediate layers, called proxy DAOs, such as RatingVectorPDAO that provide access to intermediate data structures that are usually computed from underlying data accessed via the master DAO.
The data access objects make no transactional or immutability guarantees, and do not provide mutation. An implementation is, of course, free to provide mutation.