Dynamically add managed class names to EntityManagerFactory

Question

Say I have a persistence.xml file like this:

<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>

I know I can change the persistence.xml file from code like this, but only the properties section:

Properties properties = new Properties();
properties.put("javax.persistence.jdbc.url", "<value>");
properties.put("eclipselink.logging.level", "<value>");
....
emf = Persistence.createEntityManagerFactory("pu", properties);

I can get all the Entity classes via reflection, but how can I add the class names (E1..E3 in the example) dynamically in a way similar to what I did for the properties?

I know Hibernate has a way to do it, but I'm using eclipselink. Is there a way to do it with eclipselinks JPA-implementation?

Plaul · Accepted Answer · 2019-06-21T17:01:54.990

0

I originally spent a lot of time on this problem/question and have given up on my original idea (dynamically add entity classes). So if you read this question, my own answer is, I'm pretty sure it can't be done.

edited Jun 21 '19 at 17:01

answered Jun 21 '19 at 08:14

Plaul

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there is a very manual way that I could find there: https://stackoverflow.com/a/2892654/516188 -- but you must describe the entity manually (all fields, joins...), so it's really not practical. – Emmanuel Touzery Apr 22 '21 at 07:28

Dynamically add managed class names to EntityManagerFactory

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