当继承跨越单独的JAR时,如何使用@Entity属性? [英] How to use @Entity attribute when inheritance is across separate JARs?
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问题描述
我有两个实体,其中一个继承了另一个实体,因此我在 jar1 entity1 中,而我又有一个 jar2 entity2->继承(entity1)
I have two entities where one of them inherits the other one, so I have in jar1 the entity1 and I have a jar2 the entity2->inherits(entity1)
在jar1中:
@Entity
public class Entity1 {...}
在jar2中:
@Entity
public class Entity2 extends Entity1 {...}
所以我该如何工作,它甚至没有编译为:
So how can I make this to work, it doesn't even compile saying:
An annotation processor threw an uncaught exception...
Caused by: java.lang.NullPointerException
at org.eclipse.persistence.internal.jpa.metadata.accessors.classes.EntityAccessor.discoverMappedSuperclassesAndInheritanceParents(EntityAccessor.java:224)
看似简单,但不起作用,我该怎么办?
It seems simple, but it does not work, what should I do?
更新:
这是jar2的persistencel.xml:
Here is the persistencel.xml for jar2:
<?xml version="1.0" encoding="UTF-8"?>
<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="EntityBPU" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<jta-data-source>my_datasource</jta-data-source>
<jar-file>jar1.jar</jar-file>
<properties>
<property name="eclipselink.ddl-generation" value="drop-and-create-tables"/>
</properties>
</persistence-unit>
推荐答案
从理论上讲,在不同的JAR中具有两个相关的实体并没有什么特别的.
Theoretically there's nothing special about having two related entities in different JARs.
检查环境和编译方式.
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