是否可以使用JPA和Hibernate扫描jar文件中的实体 [英] Is it possible to scan Entities in jar files using JPA and hibernate

问题描述

我有以下情况:

• 项目A-包含一些实体并且是独立的
• 项目B-包含一些实体并且是独立的
• 项目C-包含很少的实体，并且依赖于项目A&项目B.

我正在使用Maven来管理依赖关系和构建.

I am using Maven to manage dependencies and builds.

当我尝试测试项目A和项目B时，一切顺利.它们每个都有一个persistence.xml和一个单独的持久上下文.

When I try to test Project A and project B it goes through fine. Each of them has a persistence.xml and a separate persistent context.

当我运行Project C时，它会映射任何实体.我尝试使用自动检测功能，并指定了jar文件属性...但是似乎没有任何作用.

When I run Project C , It does map any of the entities. I have tried to use the auto-detect, specified the jar file attribute ... but nothing seems to work.

它给了我一个映射异常，说未知实体，不会持久存在，也不会从项目A或B中读取实体.我在这里发布了3个persistence.xml文件.

It gives me a Mapping Exception saying unknown entity and wont persist or read the Entities from Projects A or B. I have posted the 3 persistence.xml files here.

此外，我尝试使用class属性并使用相同的持久性上下文，但是它只是找不到文件.

Also, I tried using the class attribute and using the same persistent context but it just wont find the files.

我们非常感谢您的帮助.

Any help is really appreciated.

提前谢谢！

<persistence 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_1_0.xsd" version="1.0">
    <persistence-unit name="A" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <properties>
      <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle9Dialect"/>
    <property name="hibernate.connection.driver_class" value="oracle.jdbc.OracleDriver"/>
      <property name="hibernate.show_sql" value="true"/>
      <property name="hibernate.connection.username" value="username"/>
      <property name="hibernate.connection.password" value="password"/>
      <property name="hibernate.connection.url" value="jdbc:oracle:thin:@webdev.epi.web:1521/webdev.world"/>
      <property name="hibernate.max_fetch_depth" value="3"/>
      <property name="hibernate.archive.autodetection" value="class"/>
    </properties>

        </persistence-unit>
</persistence>

<persistence 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_1_0.xsd" version="1.0">
    <persistence-unit name="B" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <properties>
      <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle9Dialect"/>
    <property name="hibernate.connection.driver_class" value="oracle.jdbc.OracleDriver"/>
      <property name="hibernate.show_sql" value="true"/>
      <property name="hibernate.connection.username" value="username"/>
      <property name="hibernate.connection.password" value="password"/>
      <property name="hibernate.connection.url" value="jdbc:oracle:thin:@webdev.epi.web:1521/webdev.world"/>
      <property name="hibernate.max_fetch_depth" value="3"/>
      <property name="hibernate.archive.autodetection" value="class"/>
    </properties>

        </persistence-unit>
</persistence>

<persistence 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_1_0.xsd" version="1.0">
    <persistence-unit name="C" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <jar-file>A-0.0.1-SNAPSHOT.jar</jar-file>
                    <jar-file>B-0.0.1-SNAPSHOT.jar</jar-file>
        <properties>
      <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle9Dialect"/>
    <property name="hibernate.connection.driver_class" value="oracle.jdbc.OracleDriver"/>
      <property name="hibernate.show_sql" value="true"/>
      <property name="hibernate.connection.username" value="username"/>
      <property name="hibernate.connection.password" value="password"/>
      <property name="hibernate.connection.url" value="jdbc:oracle:thin:@webdev.epi.web:1521/webdev.world"/>
      <property name="hibernate.max_fetch_depth" value="3"/>
      <property name="hibernate.archive.autodetection" value="class"/>
    </properties>

        </persistence-unit>
</persistence>

推荐答案

实际上，我找到了一种使其工作的方法. 在专案A和B，我自动检测到我的实体，在Project C中，我明确列出了映射的类，这些实体现在已被映射，并且可以正常工作.

Actually, I found a way to make it work. In Projects A & B , I autodetect my entities and in Project C , I explicitly list the mapped classes, the entities are now getting mapped and it works.

希望它对其他人有帮助！

Hope it helps some one else !

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