@PersistenceUnit 注释不起作用

发布于 2024-12-06 01:30:23 字数 510 浏览 1 评论 0原文

我想在我的应用程序中使用 @PersistenceUnit 注释来创建应用程序管理的 EntityManager

@PersistenceUnit(unitName="primary")


private static EntityManagerFactory entityManagerFactory;        
EntityManager entityManager = entityManagerFactory.createEntityManager();

这似乎不起作用。我通过调试器运行我的代码，发现entityManagerFactory 为空。我的猜测是，使用 @PersistenceUnit 注释注入 Persistence 上下文不起作用。

我的应用程序是 CDI 应用程序。它以前不是 CDI 应用程序 - 我通过在 WEB-INF 中创建 beans.xml 文件将其转换为 CDI，我需要这样做才能执行类似的操作。

我需要在 CDI 中配置什么才能使注释正常工作吗？谢谢。

原文

I want to use the @PersistenceUnit annotation in my app to create an application managed EntityManager

@PersistenceUnit(unitName="primary")


private static EntityManagerFactory entityManagerFactory;        
EntityManager entityManager = entityManagerFactory.createEntityManager();

This doesn't seem to be working. I run my code through a debugger and discover that entityManagerFactory is null. My guess is that the injection of Persistence context with the @PersistenceUnit annotation is not working.

My app is a CDI app. It was not previously a CDI application - I converted it to CDI by creating a beans.xml file in WEB-INF, I needed to in order to do something like this.

Is there anything I need to configure within CDI to get the annotation to work? Thanks.

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裸钻 2024-12-13 01:30:23

我有一个仅使用 Java SE 运行的 JPA 应用程序。我没有 WEB-INF/beans.xml，但我有 META-INF/persistence.xml 配置文件：

<?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="JPAPU" transaction-type="RESOURCE_LOCAL">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <class>jpa.Container</class>
    <class>jpa.Item</class>
    <properties>
      <property name="javax.persistence.jdbc.url" value="jdbc:derby:D:\NetBeansProjects\JPA\jpaTestDB;create=true"/>
      <property name="javax.persistence.jdbc.password" value=""/>
      <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.EmbeddedDriver"/>
      <property name="javax.persistence.jdbc.user" value=""/>
      <property name="eclipselink.ddl-generation" value="create-tables"/>
    </properties>
  </persistence-unit>
</persistence>

Container 和 Item 是两个持久性我的 jpa 包中的类。

这是由 Netbeans 自动生成的。官方 (Sun/Oracle) Java EE 教程的持久性章节中还有一些有关在没有 Java EE 的情况下使用 JPA 的信息。

I have a JPA application running with only Java SE. I don't have a WEB-INF/beans.xml, but I do have a META-INF/persistence.xml configuration file:

<?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="JPAPU" transaction-type="RESOURCE_LOCAL">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <class>jpa.Container</class>
    <class>jpa.Item</class>
    <properties>
      <property name="javax.persistence.jdbc.url" value="jdbc:derby:D:\NetBeansProjects\JPA\jpaTestDB;create=true"/>
      <property name="javax.persistence.jdbc.password" value=""/>
      <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.EmbeddedDriver"/>
      <property name="javax.persistence.jdbc.user" value=""/>
      <property name="eclipselink.ddl-generation" value="create-tables"/>
    </properties>
  </persistence-unit>
</persistence>

Container and Item are the two persistence classes in my jpa package.

This was generated automatically by Netbeans. There is also some information about using JPA without Java EE in the official (Sun/Oracle) Java EE tutorial in the persistence chapter.

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