具有多个持久性单元的Spring Data JPA CDI集成

Question

我是Spring的新手，正在尝试在Weblogic 12c上集成Spring Data，EclipseLink和EJB。

我想使用CDI将Spring Data Repository注入到无状态EJB中，所以我遵循了Spring Data CDI集成指令并成功使用了单个持久性单元。

https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#jpd.misc.cdi-integration

由于该应用程序需要两个持久性单元来连接两个不同的数据库，因此我在persistence.xml中配置了两个具有不同名称的持久性单元。

问题来了：如何创建两个Spring Data存储库，以便RepositoryA使用持久性单元A和RepositoryB使用持久性单元B？

persistence.xml中

<?xml version="1.0" encoding="UTF-8" ?>
<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence
             http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"
             version="2.1">
    <persistence-unit name="PRIMARY_PU" transaction-type="JTA">
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
        <jta-data-source>jdbc/EMP_DS</jta-data-source>
        <class>com.smec.eis.example.springbooteval.model.Employee</class>
        <exclude-unlisted-classes>true</exclude-unlisted-classes>
        <shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>
    </persistence-unit>
    <persistence-unit name="SECONDARY_PU" transaction-type="JTA">
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
        <jta-data-source>jdbc/HR_DS</jta-data-source>
        <class>com.smec.eis.example.springbooteval.model.Job</class>
        <exclude-unlisted-classes>true</exclude-unlisted-classes>
        <shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>
    </persistence-unit>
</persistence>

主要的CDI生产者：

public class EntityManagerFactoryProducer {

    @Produces
    @ApplicationScoped
    public EntityManagerFactory createEntityManagerFactory() {
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("PRIMARY_PU");
        return emf;
    }

    public void close(@Disposes EntityManagerFactory entityManagerFactory) {
        entityManagerFactory.close();
    }

    @Produces
    @Dependent
    public EntityManager createEntityManager(EntityManagerFactory entityManagerFactory) {
        return entityManagerFactory.createEntityManager();
    }

    public void close(@Disposes EntityManager entityManager) {
        entityManager.close();
    }
}

Answer 1

TL; DR;

使用限定符声明哪个存储库应使用哪个EntityManager 。

说明

Spring Data JPA存储库默认情况下在单个EntityManager 。 CDI扩展会将所有限定符从存储库接口传播到其EntityManager选择。 由于预选赛是有效的空（在不包括@Default和@Any ），扩展使用单一EntityManager从上面的代码。

创建和添加自己的限定词注释将为您完成这项工作：

预选赛

@Qualifier
@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@interface MyFirstDatabase {

}

@Qualifier
@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@interface MySecondDatabase {

}

仓库接口

@MyFirstDatabase
public interface SomeRepository extends CrudRepository<MyEntity, Long> { … }

@MySecondDatabase
public interface SomeOtherRepository extends CrudRepository<OtherEntity, Long> { … }

客户端使用界面

public class MyComponent {

    @Inject
    @MyFirstDatabase 
    SomeRepository someRepo;

    @Inject    
    @MySecondDatabase 
    SomeOtherRepository someOtherRepo;
}

您的EntityManagerFactoryProducer ：

public class EntityManagerFactoryProducer {

    @Produces
    @ApplicationScoped
    @MyFirstDatabase
    public EntityManagerFactory createEntityManagerFactory() {
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("PRIMARY_PU");
        return emf;
    }

    @Produces
    @ApplicationScoped
    @MySecondDatabase
    public EntityManagerFactory createEntityManagerFactory() {
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("SECONDARY_PU");
        return emf;
    }

    public void close(@Disposes EntityManagerFactory entityManagerFactory) {
        entityManagerFactory.close();
    }

    @Produces
    @Dependent
    @MyFirstDatabase
    public EntityManager createEntityManager(@MyFirstDatabase EntityManagerFactory entityManagerFactory) {
        return entityManagerFactory.createEntityManager();
    }

    @Produces
    @Dependent
    @MySecondDatabase
    public EntityManager createEntityManager(@MySecondDatabase EntityManagerFactory entityManagerFactory) {
        return entityManagerFactory.createEntityManager();
    }

    public void close(@Disposes EntityManager entityManager) {
        entityManager.close();
    }
}

上面的代码假设您使用的实体类型在两个数据源中是不同的。 如果需要使用相同的实体类型，则可以创建一个基础存储库接口，并使用@NoRepositoryBean和两个派生接口对其进行注释，类似于上面的代码。

Answer 2

基于mp911de的答案。 EntityManagerFactoryProducer需要另外两个关闭方法，否则在Weblogic上部署将失败。

public class EntityManagerFactoryProducer {

    @Produces
    @ApplicationScoped
    @PrimaryEM
    public EntityManagerFactory createEntityManagerFactory() {
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("PRIMARY_PU");
        return emf;
    }

    @Produces
    @Dependent
    @PrimaryEM
    public EntityManager createEntityManager(@PrimaryEM EntityManagerFactory entityManagerFactory) {
        EntityManager em = entityManagerFactory.createEntityManager();
        return em;
    }

    @Produces
    @ApplicationScoped
    @SecondaryEM
    public EntityManagerFactory createSecondaryEntityManagerFactory() {
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("SECONDARY_PU");
        return emf;
    }

    @Produces
    @Dependent
    @SecondaryEM
    public EntityManager createSecondaryEntityManager(@SecondaryEM EntityManagerFactory entityManagerFactory) {
        EntityManager em = entityManagerFactory.createEntityManager();
        return em;
    }

    public void close(@Disposes @PrimaryEM EntityManager entityManager) {
        entityManager.close();
    }


    public void close(@Disposes @PrimaryEM EntityManagerFactory entityManagerFactory) {
        entityManagerFactory.close();
    }

    public void closeSecondary(@Disposes @SecondaryEM EntityManager entityManager) {
        entityManager.close();
    }

    public void closeSecondary(@Disposes @SecondaryEM EntityManagerFactory entityManagerFactory) {
        entityManagerFactory.close();
    }