3

我创建了一个可以使用 SQL Server 或 Neo4j 作为数据库的 Java 应用程序，而无需触及应用程序层，我只是修改了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>

我现在必须使用 Spring 应用程序来做同样的事情。我已经开始学习 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与第一个应用程序一样？我的意思是没有 Hibernate OGM 提供程序，我可以代替HibernateJpaVendorAdapter它以使应用程序在 Neo4j 而不是 SQL Server 上运行？

提前致谢。

PS：我检查了 Spring Data，但在定义实体（@NodeEntity、@GraphId、@RelatedTo 等）方面发现了另一个差异。我被要求不要触摸应用程序代码。

4

2 回答 2

2

这是下面的Java配置类（注意我使用的是spring boot，您可以根据您的要求进行修改）

@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;
    }

}

关于你关于@NodeEntity @GraphId 等的第二个问题。类似于休眠OGM sprig 使用spring-data 为nosql 提供jpa 实现，用于redis、mongodb、cassandra、hbase、couchdb、solr、elasticsearch 等多个nosql 数据存储。@NodeEnity并且在 neo4j 中使用了 @GraphId

于 2015-10-28T14:17:47.567 回答
0

我使用 OGM Hibernate 为 Neo4j 添加 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 中（用于 Java 7 项目）

    <dependency>
        <groupId>org.hibernate.ogm</groupId>
        <artifactId>hibernate-ogm-neo4j</artifactId>
        <version>4.1.0.Final</version>
    </dependency>
于 2017-11-10T09:26:05.537 回答