Question

我需要在没有persistence.xml的代码中创建EntityManager ... 我有



props.put("openjpa.ConnectionURL", "jdbc:sqlserver://databasehost:3306; DatabaseName=dbname; selectMethod=cursor;create=true");
    props.put("openjpa.ConnectionDriverName","com.mysql.jdbc.Driver");
    props.put("openjpa.ConnectionUserName", "dbname");
    props.put("openjpa.ConnectionPassword", "password");
    props.put("openjpa.jdbc.SynchronizeMappings", "buildSchema");
    props.put("openjpa.Log", "DefaultLevel=WARN, Runtime=INFO, Tool=INFO, SQL=TRACE");
    props.put("openjpa.RuntimeUnenhancedClasses", "supported");

    EntityManagerFactory factory = Persistence.createEntityManagerFactory("wp");
    em = factory.createEntityManager(props);

..当em = factory.createEntityManager（props）被调用时，我得到：


javax.persistence.PersistenceException: No persistence providers available for "wp" after trying the following discovered implementations: org.apache.openjpa.persistence.PersistenceProviderImpl
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:182)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:72)
    at dao.wp.WP_EMH.getCurrentEntityManager(WP_EMH.java:27)

据我所知，没有提及标记

表示的persistence.xml中的内容

PROVIDER- org.apache.openjpa.persistence.PersistenceProviderImpl - / PROVIDER

我应该如何将其添加到属性？或者如何解决？我的第二个问题是在persistence.xml中添加了实体类。如何用属性解决这个问题？

感谢

Answer 1

方法

javax.persistence.Persistence.createEntityManagerFactory(
    String persistenceUnitName);

需要persistence.xml的配置。尝试提供您的房产地图

javax.persistence.Persistence.createEntityManagerFactory(
    String persistenceUnitName, Map properties);

显然，财产集是不完整的;例如，它缺少持久化的类名：

properties.put("openjpa.MetaDataFactory", "jpa(Types=FQN.class1;FQN.class2;...)");

OpenJPA在没有persistence.xml的代码中创建EntityManager，具有属性

1 个答案: