关于jpa：在OSGI环境中同时使用OpneJPA和Hibernate


Using both OpneJPA and Hibernate in OSGI environment

我正在编写一个模块来保留一些数据，并使用OpenJPA作为持久性提供程序。但是，现在我想为用户提供一个配置选项，以便用户在OpenJPA和hibernate之间切换。因此，我编写了一个新的DaoFactory类来创建EntityManagerFactory，并在persistence.xml中为hibernate创建了新的持久性单元(My-PU-Hibernate)。

现在，当我创建EntityManagerFactory时出现问题。我的代码是，

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Persistence.createEntityManagerFactory("My-PU-Hibernate", hibernatePropertyMap);

我的persistence.xml

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<persistence version="2.0"
             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">

    <persistence-unit name="My-PU-OpenJPA" transaction-type="RESOURCE_LOCAL">
        <class>org.example.testproject.jpa.openjpa.entity.AttachmentDAOImpl</class>
    </persistence-unit>

    <persistence-unit name="My-PU-Hibernate" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <class>org.example.testproject.jpa.openjpa.entity.AttachmentDAOImpl</class>
    </persistence-unit>

</persistence>

我的Hibernate属性映射为

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"hibernate.connection.datasource", datasource
"hibernate.dialect","org.hibernate.dialect.MySQLDialect"
"hibernate.hbm2ddl.auto","update"
"hibernate.cache.provider_class","org.hibernate.cache.NoCacheProvider"
"hibernate.cache.use_query_cache","false"
"hibernate.cache.use_second_level_cache","false"

这将选择OpneJPA PersistenceProvider作为正确的持久性提供程序，并从OpenJPA持久性提供程序创建EntityManagerFactory。创建EntityManagerFactory时，还会发出以下警告。

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WARN   [Start Level Event Dispatcher] openjpa.Runtime - The configuration property named"openjpa.Id" was not recognized and will be ignored, although the name closely matches a valid property called"openjpa.Id".

因此，当我尝试创建实体管理器时，会出现以下错误。

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<openjpa-2.2.0-wso2v1-r128166:129108 fatal user error> org.apache.openjpa.persistence.ArgumentException: A JDBC Driver or DataSource class name must be specified in the ConnectionDriverName property. Available properties in configuration are"org.apache.openjpa.jdbc.conf.JDBCConfigurationImpl@442ce698".
at org.apache.openjpa.jdbc.schema.DataSourceFactory.newDataSource(DataSourceFactory.java:72)
at org.apache.openjpa.jdbc.conf.JDBCConfigurationImpl.createConnectionFactory(JDBCConfigurationImpl.java:844)
at org.apache.openjpa.jdbc.conf.JDBCConfigurationImpl.getDBDictionaryInstance(JDBCConfigurationImpl.java:602)
at org.apache.openjpa.jdbc.meta.MappingRepository.endConfiguration(MappingRepository.java:1510)
at org.apache.openjpa.lib.conf.Configurations.configureInstance(Configurations.java:518)
at org.apache.openjpa.lib.conf.Configurations.configureInstance(Configurations.java:443)
at org.apache.openjpa.lib.conf.PluginValue.instantiate(PluginValue.java:104)
at org.apache.openjpa.conf.MetaDataRepositoryValue.instantiate(MetaDataRepositoryValue.java:68)
at org.apache.openjpa.lib.conf.ObjectValue.instantiate(ObjectValue.java:83)
at org.apache.openjpa.conf.OpenJPAConfigurationImpl.newMetaDataRepositoryInstance(OpenJPAConfigurationImpl.java:968)
at org.apache.openjpa.conf.OpenJPAConfigurationImpl.getMetaDataRepositoryInstance(OpenJPAConfigurationImpl.java:959)
at org.apache.openjpa.kernel.AbstractBrokerFactory.makeReadOnly(AbstractBrokerFactory.java:638)
at org.apache.openjpa.kernel.AbstractBrokerFactory.newBroker(AbstractBrokerFactory.java:203)
at org.apache.openjpa.kernel.DelegatingBrokerFactory.newBroker(DelegatingBrokerFactory.java:156)
at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:227)
at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:154)
at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:60)

我认为上述警告和错误是由于选择了错误的PersistenceProvider引起的。我已经调试了代码，并验证了hibernate持久性提供程序也已加载到OSGI环境中。我将geronimo-jpa_2.0_spec v1.0用作javax.persistence供应商。

是否有关于如何选择正确的持久性提供程序的想法？

我能够通过如下方法解决逻辑问题。 IMO这是不正确的修复程序，因为Ejb3Configuration已弃用。需要找到适当的解决方案。

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//Imports
import org.hibernate.ejb.Ejb3Configuration;
import org.hibernate.ejb.HibernatePersistence;

//My Logic  
        Ejb3Configuration cfg = new Ejb3Configuration();
        cfg.addAnnotatedClass(AttachmentDAOImpl.class);
        this.entityManagerFactory = cfg.createEntityManagerFactory(propertyMap);