Question

我正在编写一个模块来保存一些数据并使用OpenJPA作为持久性提供程序。但现在我想为用户提供一个配置选项，以便在OpenJPA和hibernate之间切换。所以我写了一个新的DaoFactory类来创建EntityManagerFactory并在My-PU-Hibernate中为hibernate创建了新的持久性单元（persistence.xml）。

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

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

我的persistence.xml

<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属性映射是，

"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"

这会选择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一个EntityManagerFactory。它在创建EntityManagerFactory时也会发出以下警告。

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，它会出现以下错误。

<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)

我认为由于选择了错误的PersistenceProvider，发生了上述警告和错误。我已经验证了代码，并验证了hibernate持久性提供程序也在OSGI环境中加载。我使用geronimo-jpa_2.0_spec v1.0作为javax.persistence供应商。

有关如何选择正确的持久性提供程序的任何想法？

Answer 1

我能够通过修复逻辑来解决问题，如下所示。 IMO这不是正确的修复，因为不推荐使用Ejb3Configuration。需要找到合适的解决方案。

//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);

在OSGI环境中使用OpneJPA和Hibernate

1 个答案: