Creating a JPA Repository

Which is the correct way to configure JPA repository?

Creating a JPA Repository

1. Step 1: Create an interface with the name ExchangeValueRepository and extends the JpaRepository class.
2. Step 2: Open CurrencyExchageController.
3. Step 3: Create a query method in the ExcahngeValueRepository.
4. ExcahngeValueRepository.java.
5. Step 4: In the CurrencyExchangeController.

How do I use Spring repository?

Example

1. Step 1: Create a Simple Spring Boot Project.
2. Step 2: Add the spring-context dependency in your pom.
3. Step 3: In your project create two packages and name the package as “entity” and “repository”.
4. Step 4: Create an entity class for which we will implement a spring repository.

What does @repository do in Spring?

Spring @Repository annotation is used to indicate that the class provides the mechanism for storage, retrieval, search, update and delete operation on objects.

How do I set up EntityManagerFactory?

Configuring the Entity Manager Factory Bean Create a new LocalContainerEntityManagerFactoryBean object. We need to create this object because it creates the JPA EntityManagerFactory. Configure the used datasource. Configure the Hibernate specific implementation of the JpaVendorAdapter interface.

What do you have to configure to use JPA with Spring?

If we want to use JPA with MySQL database, we need the mysql-connector-java dependency. We’ll also need to define the DataSource configuration. We can do this in a @Configuration class or by using standard Spring Boot properties. Spring Boot will automatically configure a data source based on these properties.

Is @repository a bean?

1. @Repository Annotation. In the spring framework, @Component annotation marks a Java class as a bean so the component-scanning mechanism can find it and create its instance into the application context.

What is the difference between @component @repository @service and @controller?

@Component is a generic stereotype for any Spring-managed component or bean. @Repository is a stereotype for the persistence layer. @Service is a stereotype for the service layer. @Controller is a stereotype for the presentation layer (spring-MVC).

What is difference between EntityManagerFactory and EntityManager?

EntityManagerFactory vs EntityManager EntityManager: whenever using spring avoid managing/using EntityManagerFactory since Spring manages concurreny for you. The entity manger injected by @PersistenceContext is thread safe. While EntityManagerFactory instances are thread-safe, EntityManager instances are not.

What is @service and @repository in Spring?

@Component is a generic stereotype for any Spring-managed component. @Service annotates classes at the service layer. @Repository annotates classes at the persistence layer, which will act as a database repository.

What do @component @service @controller and @repository do?

Can I use @service instead of @repository?

According to documentaion @Repository , @Service , @Controller are all synonyms. They all are just specializations of @Component annotation. So, generally, they can be used one instead of other.