Question

我创建了一个Java应用程序，可以使用SQL Server或Neo4j作为数据库，而无需触及应用程序层，我只需修改提供程序和连接信息，如下所示：

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
             version="2.0">

    <persistence-unit name="jpa-tutorial" transaction-type="RESOURCE_LOCAL">
        <!--For SQL Server-->
        <!--provider>org.hibernate.ejb.HibernatePersistence</provider>
        <!--class>com.mycompany.hibernate.Atom</class-->

        <!--For Neo4j-->
        <provider>org.hibernate.ogm.jpa.HibernateOgmPersistence</provider>


        <properties>
            <!--For Neo4j-->
            <property name="hibernate.ogm.datastore.provider" value="neo4j_embedded" />
            <property name="hibernate.ogm.neo4j.database_path" value="D:/Stage/Neo4j/NEO4J_HOME_4/data/graph.db" />

            <!--For SQL Server-->
            <!--property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/atom" />
            <property name="javax.persistence.jdbc.user" value="root" />
            <property name="javax.persistence.jdbc.password" value="" />

            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.hbm2ddl.auto" value="updatr" /-->
         </properties>

    </persistence-unit>
</persistence>

我现在要用Spring应用程序做同样的事情。我开始学习Spring但发现了一个全新的逻辑。例如，有一个不同的JPA提供者：

<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">

这是否意味着没有办法像第一个应用程序那样做？我的意思是我没有Hibernate OGM提供程序可以放在HibernateJpaVendorAdapter的位置，以使应用程序在Neo4j而不是SQL Server上运行？

提前致谢。

PS：我查看了Spring Data但发现了定义实体的另一个区别（@NodeEntity，@ GraphId，@ RelatedTo等）。我要求不要触摸应用程序代码。

Answer 1

以下是Java配置类（注意我使用spring boot，你可以根据你的要求进行修改）

@Configuration
@EnableJpaRepositories(basePackages = {
        "com.kp.swasthik.mongo.dao" }, entityManagerFactoryRef = "mongoEntityManager", transactionManagerRef = "mongoTransactionManager")
public class MongDbConfig {


    @Bean(name = "mongoEntityManager")
    public LocalContainerEntityManagerFactoryBean mongoEntityManager() throws Throwable {

        Map<String, Object> properties = new HashMap<String, Object>();
        properties.put("javax.persistence.transactionType", "resource_local");
        properties.put("hibernate.ogm.datastore.provider","mongodb");
        properties.put("hibernate.ogm.datastore.host","localhost");
        properties.put("hibernate.ogm.datastore.port","27017");
        properties.put("hibernate.ogm.datastore.database", "kpdb");
        properties.put("hibernate.ogm.datastore.create_database", "true");

        LocalContainerEntityManagerFactoryBean entityManager = new LocalContainerEntityManagerFactoryBean();
        entityManager.setPackagesToScan("com.kp.swasthik.mongo.domain");
        entityManager.setPersistenceUnitName("mongoPersistenceUnit");
        entityManager.setJpaPropertyMap(properties);
        entityManager.setPersistenceProviderClass(HibernateOgmPersistence.class);
        return entityManager;
    }

    @Bean(name = "mongoTransactionManager")
    public PlatformTransactionManager transactionManager() throws Throwable {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(mongoEntityManager().getObject());
        return transactionManager;
    }

}

关于@NodeEntity @GraphId的第二个问题等。与hibernate类似，OGM sprig使用spring-data为reds，mongodb，cassandra，hbase，couchdb，solr，elasticsearch等nosql数据存储提供jpa实现。 .NodeEnity和@GraphId用于neo4j

Answer 2

我使用OGM Hibernate为Neo4j添加了Java Config

@Configuration
@EnableTransactionManagement
@JpaPackagesToScan(Entity.class)
public class RepositoryConfig {
    /**
     * Neo4J OGM EntityManager config
     */
    @Bean
    public LocalContainerEntityManagerFactoryBean entityManager(JpaPackagesToScanHolder holder) throws Throwable {

        Map<String, Object> properties = new HashMap<String, Object>();
        properties.put("javax.persistence.transactionType", "JTA");
        properties.put("hibernate.ogm.datastore.provider", "neo4j_embedded");
        properties.put("hibernate.ogm.datastore.database", "my-db");
        properties.put("hibernate.ogm.neo4j.database_path", "/mnt/graph.db");
        properties.put("hibernate.dialect", "org.hibernate.ogm.datastore.neo4j.Neo4jDialect");

        LocalContainerEntityManagerFactoryBean entityManager = new LocalContainerEntityManagerFactoryBean();
        entityManager.setPackagesToScan(holder.toStringArray());
        entityManager.setPersistenceUnitName("my-pu");
        entityManager.setJpaPropertyMap(properties);
        entityManager.setPersistenceProviderClass(HibernateOgmPersistence.class);
        return entityManager;
    }


    @Bean
    public PlatformTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) throws Throwable {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(entityManagerFactory);
        return transactionManager;
    }

}

并添加到pom（用于Java 7项目）

    <dependency>
        <groupId>org.hibernate.ogm</groupId>
        <artifactId>hibernate-ogm-neo4j</artifactId>
        <version>4.1.0.Final</version>
    </dependency>

用于Spring配置的Hibernate OGM提供程序

2 个答案: