JDBC, Transactions, Spring Data JPA
July 31, 2021
M03 Q28 How are Spring Data repositories implemented by Spring at runtime?
Spring Repositories are implemented at runtime by SimpleJpaRepository by default
When application context is starting up, Spring will scan for all classes annotated with @Configuration. When @Configuration class with @EnableJpaRepositories will be detected, JpaRepositoriesRegistrar with JpaRepositoryConfigExtension will be used to create beans for repositories in packages pointed out by basePackages field in @EnableJpaRepositories. JpaRepositoryFactoryBean will use JpaRepositoryFactory to create beans based on bean definitions and by default will create instance of SimpleJpaRepository class for each Repository interface.
Class used for implementation of Repository interface can be customized on:
- Global level, by using
repositoryBaseClassfield from@EnableJpaRepositoriesannotation
- Single Dao/Repository by creating separate interface and Impl class for behavior that you want to customize
