Spring Data project

The Spring Data project is an umbrella project that offers a familiar way to create our data access layer on a wide range of database technologies. It means there are high-level abstractions to interact with different kinds of data structures, such as the document model, column family, key-value, and graphs. Also, the JPA specification is fully supported by the Spring Data JPA project.

These modules offer powerful object-mapping abstractions for our domain model.

There is support for different types of data structures and databases. There is a set of sub-modules to keep the framework modularity. Also, there are two categories of these sub-modules: the first one is a subset of projects supported by the Spring Framework Team and the second one is a subset of sub-modules provided by the community.

Projects supported by the Spring Team include:

• Spring Data Commons
• Spring Data JPA
• Spring Data MongoDB
• Spring Data Redis
• Spring Data for Apache Cassandra

Projects supported by the community include:

• Spring Data Aerospike
• Spring Data ElasticSearch
• Spring Data DynamoDB
• Spring Data Neo4J

The base of the repositories interfaces chain is the Repository interface. It is a marker interface, and the general purpose is to store the type information. The type will be used for other interfaces that extend it.

There is also a CrudRepository interface. It is the most important, and the name is self-explanatory; it provides a couple of methods to perform CRUD operations, and it provides some utility methods, such as count(), exists(), and deleteAll(). Those are the most important base interfaces for the repository implementations.