SpringData JPA @EnableJpaRepositories Anotasyonu

Giriş
Şu satırı dahil ederiz.

import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

- JPA için @EnableJpaRepositories kullanılır.
- Couchbase için @EnableCouchbaseRepositories kullanılır.

Repository sınıfları klasik anlamda bean olmadıkları iiçin ayrıca taranmaları gerekir. @ComponentScan ile yüklenmezler

Belirtilen paketlerdeki sınıflar için kod üretir ve Spring'e tanıtır. Üretilen kod SimpleJpaRepository sınıfından kalıtır.

Açıklaması şöyle.

In SpringData you have @EnableJpaRepositories + entire underlying scanning and repository bean generation mechanism and there is no need to mark your repository interfaces (or custom classes) with @Repository.

Açıklaması şöyle.

In order to start leveraging the Spring Data programming model with JPA, a DAO interface needs to extend the JPA specific Repository interface – JpaRepository. This will enable Spring Data to find this interface and automatically create an implementation for it.

Kodun şöyle olduğunu varsayalım. Bu durumda com.myproject.dao.jpa paketini belirtmemiz gerekir.

com.myproject
 - Application.java
com.myproject.configuration
 - ServiceConfiguration.java
 - OtherConfiguration.java
com.myproject.dao.jpa
 - .. your repositories..
com.myproject.domain.jpa
 - .. your @Entity classes...

basePackages Alanı
Örnek

Şöyle yaparız.

@SpringBootApplication(scanBasePackages = {"com.johndoe", "com.johndoe.repos"})
@EnableJpaRepositories("com.johndoe.repos")
public class MyApplication {
  public static void main(String[] args) {        
    SpringApplication.run(MyApplication.class, args);
  }
}

entityManagerFactoryRef  Alanı
Örnek
Şöyle yaparız.

@EnableJpaRepositories(basePackages="com.foo.bar",
 entityManagerFactoryRef ="entityManager", transactionManagerRef = "txManager")

Örnek
İki tane veri tabanı olsaydı application.properties için şöyle yaparız.

# MySQL DB - "foo"
spring.datasource.url=jdbc:mysql://XXX:3306/foo?currentSchema=public
spring.datasource.username=XXX
spring.datasource.password=XXX
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
# MySQL DB - "bar"
bar.datasource.url=jdbc:mysql://YYYY:3306/bar?currentSchema=public
bar.datasource.username=YYYY
bar.datasource.password=YYYY
bar.datasource.driver-class-name=com.mysql.jdbc.Driver
# JPA
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=none
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect

İlk repository için şöyle yaparız.

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(entityManagerFactoryRef = "entityManagerFactory",
        transactionManagerRef = "transactionManager",
        basePackages = {"com.foobar.foo.repo"})
public class FooDbConfig {

  @Primary
  @Bean(name = "dataSource")
  @ConfigurationProperties(prefix = "spring.datasource")
  public DataSource dataSource() {
    return DataSourceBuilder.create().build();
  }

  @Primary
  @Bean(name = "entityManagerFactory")
  public LocalContainerEntityManagerFactoryBean entityManagerFactory(
    EntityManagerFactoryBuilder builder, @Qualifier("dataSource") DataSource dataSource) {
    return builder
      .dataSource(dataSource)
      .packages("com.foobar.foo.domain")
      .persistenceUnit("foo")
      .build();
  }

  @Primary
  @Bean(name = "transactionManager")
  public PlatformTransactionManager transactionManager(
    @Qualifier("entityManagerFactory") EntityManagerFactory entityManagerFactory) {
    return new JpaTransactionManager(entityManagerFactory);
  }
}

İkincisi için şöyle yaparız. basePackages farklı bir isimle kullanılır.

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(entityManagerFactoryRef = "barEntityManagerFactory",
  transactionManagerRef = "barTransactionManager", basePackages = {"com.foobar.bar.repo"})
public class BarDbConfig {

  @Bean(name = "barDataSource")
  @ConfigurationProperties(prefix = "bar.datasource")
  public DataSource dataSource() {
    return DataSourceBuilder.create().build();
  }

  @Bean(name = "barEntityManagerFactory")
  public LocalContainerEntityManagerFactoryBean barEntityManagerFactory(
  EntityManagerFactoryBuilder builder, @Qualifier("barDataSource") DataSource dataSource){
    return builder
      .dataSource(dataSource)
      .packages("com.foobar.bar.domain")
      .persistenceUnit("bar")
      .build();
  }

  @Bean(name = "barTransactionManager")
  public PlatformTransactionManager barTransactionManager(
    @Qualifier("barEntityManagerFactory") EntityManagerFactory barEntityManagerFactory) {
    return new JpaTransactionManager(barEntityManagerFactory);
  }
}

Örnek
Şöyle yaparız.

@Configuration
@EnableTransactionManagement
@ComponentScan("com.myexample.demo")
@PropertySource(value="classpath:application.yml")
@EnableJpaRepositories(
            basePackages = "com.myexample.demo",
            entityManagerFactoryRef = "myEntityManager",
            transactionManagerRef = "myTransactionManager")
public class DatabaseExample {


  @Bean(name = "myEntityManager")
  @Primary
  public LocalContainerEntityManagerFactoryBean athenaEntityManager() {
    LocalContainerEntityManagerFactoryBean em =
      new LocalContainerEntityManagerFactoryBean();
    ...

    return em;
  }

  @Bean(name = "myTransactionManager")
  @Primary
  public PlatformTransactionManager athenaTransactionManager() {
    JpaTransactionManager transactionManager = new JpaTransactionManager();
    ...
    return transactionManager;
  }
  ...
}

excludeFilters Alanı
Şöyle yaparız

@SpringBootApplication
@EnableJpaRepositories(excludeFilters = {
  @ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE, classes = {
    DataRepository.class})
})

repositoryBaseClass Alanı

Eğer repository sınıflarımı için farklı bir ata sınıf kullanmak istersek bu alanı kullanırız. Şöyle yaparız. Burada ata sınıf olarak "SpringData JPA MongoDB Expressions" kullanılıyor

@Configuration
@EnableJpaRepositories(repositoryBaseClass = ExpressionsRepositoryImpl.class)
class ApplicationConfiguration { … }

repositoryFactoryBeanClass Alanı

Açıklaması şöyle.

Spring data uses JpaRepositoryFactory by default to find the right implementation for your repository. You can define a custom factory by the config @EnableJpaRepositories(repositoryFactoryBeanClass = CustomRepositoryFactoryBean.class)