KeyValue

Spring Data KeyValue provides easy configuration and access to Map like structures that associate values with unique keys. It offers both low-level and high-level abstractions for interacting with the underlying data structure, freeing the user from infrastructural concerns.

The key-value abstraction within Spring Data Key Value requires an Adapter that shields the native store implementation, freeing up KeyValueTemplate to work on top of any key-value pair-like structure. Keys are distributed across Keyspaces. Unless otherwise specified, the class name is used as the default keyspace for an entity. The following interface definition shows the KeyValueOperations interface, which is the heart of Spring Data Key-Value:

interface KeyValueOperations {

    <T> T insert(T objectToInsert);                               (1)

    void update(Object objectToUpdate);                           (2)

    void delete(Class<?> type);                                   (3)

    <T> T findById(Object id, Class<T> type);                     (4)

    <T> Iterable<T> findAllOf(Class<T> type);                     (5)

    <T> Iterable<T> find(KeyValueQuery<?> query, Class<T> type);  (6)

    //... more functionality omitted.

}

1	Inserts the given entity and assigns an ID (if required).
2	Updates the given entity.
3	Removes all entities of the matching type.
4	Returns the entity of the given type with its matching ID.
5	Returns all entities of the matching type.
6	Returns a `List` of all entities of the given type that match the criteria of the query.

Keyspaces

Keyspaces define the part of the data structure in which the entity should be kept. This concept is similar to collections in MongoDB and Elasticsearch, cores in Solr, and tables in JPA. By default, the keyspace of an entity is extracted from its type, but you can also store entities of different types within one keyspace.