Spring Data JPA is a module of the larger Spring Data family that makes it easy to implement JPA-based repositories. JPA stands for Java Persistence API, which is a specification for persisting Java objects to a relational database using popular ORM technologies like Hibernate. Spring Data JPA adds a layer on top of JPA, using all the features defined by the JPA specification, especially the entity and association mappings, the entity lifecycle management, and JPA’s query capabilities. It also adds its own features like a no-code implementation of the repository pattern and the creation of database queries from method names.

Implementing a data access layer of an application has been cumbersome for quite a while, but Spring Data JPA aims to significantly improve the implementation of data access layers by reducing the effort to the amount that’s actually needed. As a developer, you write your repository interfaces, including custom finder methods, and Spring will provide the implementation automatically. Some of the cool features provided by Spring Data JPA are:

• No-code Repositories: Spring Data JPA can generate the implementation of the repository interface automatically, without requiring you to write boilerplate code.
• Query Methods: You can declare an interface extending Repository or one of its subinterfaces and type it to the domain class and ID type that it represents. Then, you can declare query methods on that interface and Spring Data JPA will automatically generate an implementation for you.
• Pagination Support: Spring Data JPA provides built-in support for pagination, making it easy to retrieve large amounts of data in smaller chunks.
• Dynamic Query Execution: Spring Data JPA allows you to create dynamic queries at runtime, which can be useful when you need to build queries based on user input or other runtime conditions.
• Type-Safe JPA Queries: Spring Data JPA supports Querydsl predicates, which allows you to write type-safe JPA queries.
• Validation of @Query Annotated Queries at Bootstrap Time: Spring Data JPA validates @Query annotated queries at bootstrap time, which can help catch errors early in the development process.

To use Spring Data JPA in your application, you only need to add the spring-boot-starter-data-jpa artifact and your JDBC driver to your Maven build. The Spring Boot Starter includes all required dependencies and activates the default configuration.