Spring @Repository Annotation Example

← Back to All Spring Data JPA Tutorials

In this quick article, we will discuss how to use the Spring or Spring Boot @Repository annotation with an example.

Spring @Repository Overview  

DAO or Repository classes usually represent the database access layer in an application and should be annotated with @Repository annotation.

As of Spring 2.5, this annotation also serves as a specialization of @Component, allowing for implementation classes to be autodetected through classpath scanning.

 
@Repository annotation internally annotated with @Component annotation as shown in the below diagram:

Whenever we annotated a class with @Repository annotation then Spring Container will automatically create a Spring bean for that class.

@Repository Annotation Example

Let's create a simple Spring boot application to bootstrap quickly. Add the below dependencies to your pom.xml file.

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

Create User JPA Entity

Let's create a simple User JPA entity that maps with the users table in the database:

@Entity
@Table(name = "users")
class User {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;
    private String name;

    public User(int id, String name) {
        super();
        this.id = id;
        this.name = name;
    }

    public User() {}

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

Create UserRepository

Next, create a UserRepository interface and annotate with @Repository annotation:

@Repository
interface UserRepository extends JpaRepository < User, Integer > {

}

Note Spring Data JPA automatically provides an implementation for the above interface.

Create UserService and UserServiceImpl

interface UserService {
    public void saveUser(User user);
}

@Service
class UserServiceImpl implements UserService {

    @Autowired
    private UserRepository userRepository;

    @Override
    public void saveUser(User user) {
        userRepository.save(user);
    }
}

Testing

Let's write a code to test UserRepository to save user objects into database table:

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        ConfigurableApplicationContext applicationContext = SpringApplication.run(DemoApplication.class, args);
        UserService userService = (UserService) applicationContext.getBean("userServiceImpl");
        userService.saveUser(new User(10, "Ramesh"));
    }
}

Complete Code

Here is the complete code for your reference:

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import org.springframework.stereotype.Service;

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        ConfigurableApplicationContext applicationContext = SpringApplication.run(DemoApplication.class, args);
        UserService userService = (UserService) applicationContext.getBean("userServiceImpl");
        userService.saveUser(new User(10, "Ramesh"));
    }
}

@Entity
@Table
class User {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;
    private String name;

    public User(int id, String name) {
        super();
        this.id = id;
        this.name = name;
    }

    public User() {}

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

@Repository
interface UserRepository extends JpaRepository < User, Integer > {

}

interface UserService {
    public void saveUser(User user);
}

@Service
class UserServiceImpl implements UserService {

    @Autowired
    private UserRepository userRepository;

    @Override
    public void saveUser(User user) {
        userRepository.save(user);
    }
}

Note that we have created ApplicationContext and retrieved bean using the getBean() method:

ConfigurableApplicationContext  applicationContext =  SpringApplication.run(DemoApplication.class, args);
UserService userService = (UserService) applicationContext.getBean("userServiceImpl");
userService.saveUser(new User(10, "Ramesh"));

Usage of @Repository annotation in Spring Data JPA Repository

@Repository
interface UserRepository extends JpaRepository < User, Integer > {

}

Related Spring and Spring Boot Annotations

• Spring Boot @Bean Annotation Example
• Spring @Qualifier Annotation Example
• Spring @Autowired Annotation with Example
• Spring @Bean Annotation with Example
• Spring @Configuration Annotation with Example
• Spring @PropertySource Annotation with Example
• Spring @Import Annotation with Example
• Spring @ImportResource Annotation Example
• Spring - @Lazy Annotation Example
• Spring - @Primary Annotation Example
• Spring @PostConstruct and @PreDestroy Example
• Spring @Repository Annotation
• Spring @Service Annotation 
• The Spring @Controller and @RestController Annotations
• Spring Boot @Component, @Controller, @Repository and @Service
• Spring @Scope annotation with Prototype Scope Example
• Spring @Scope annotation with Singleton Scope Example
• Spring Boot @PathVariable
• Spring Boot @ResponseBody
• Spring @RequestBody - Binding Method Parameters to Request Body
• Spring Boot @ResponseStatus Annotation
• Spring Boot - Creating Asynchronous Methods using @Async Annotation
• @SpringBootTest Spring Boot Example
• @SpringBootTest vs @WebMvcTest
• @DataJpaTest Spring Boot Example
• Spring @PostConstruct and @PreDestroy Example
• Spring @GetMapping, @PostMapping, @PutMapping, @DeleteMapping and @PatchMapping
• Spring Boot @EnableAutoConfiguration Annotation with Example
• Spring Boot @SpringBootApplication Annotation with Example

← Back to All Spring Data JPA Tutorials

Free Spring Boot Tutorial | Full In-depth Course | Learn Spring Boot in 10 Hours

---

Watch this course on YouTube at Spring Boot Tutorial | Fee 10 Hours Full Course