【发布时间】:2019-08-28 15:54:59
【问题描述】:
假设我有一个像这样的 persistence.xml 文件:
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="pu" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>entity.E1</class>
<class>entity.E2</class>
<class>entity.E3</class>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="javax.persistence.jdbc.url" value="jdbc:derby:memory:myTestDB;create=true"/>
<property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.EmbeddedDriver"/>
<property name="eclipselink.logging.level" value="WARNING"/>
<property name="eclipselink.canonicalmodel.subpackage" value="test"/>
<property name="javax.persistence.schema-generation.database.action" value="create"/>
</properties>
</persistence-unit>
</persistence>
我知道我可以通过这样的代码更改 persistence.xml 文件,但只能更改属性部分:
Properties properties = new Properties();
properties.put("javax.persistence.jdbc.url", "<value>");
properties.put("eclipselink.logging.level", "<value>");
....
emf = Persistence.createEntityManagerFactory("pu", properties);
我可以通过反射获取所有实体类,但是如何以类似于我为属性所做的方式动态添加类名(示例中为 E1..E3)?
我知道 Hibernate 有 a way to do it,但我使用的是 eclipselink。 有没有办法通过 eclipselinks JPA 实现来做到这一点?
【问题讨论】:
标签: jpa eclipselink persistence.xml