当持久性存在时，为什么持久性单元名为 null.xml

java entitymanager wildfly

2022-09-04 21:53:21

我正在使用Wildfly 8.1和包含实体的EJB项目（EJB 3.2）。当尝试将实体管理器注入我的一个Bean时，我得到以下内容：

JBAS011440: Can't find a persistence unit named null in deployment \"EntitiesProject.jar\""},
"JBAS014771: Services with missing/unavailable dependencies" => [
    "jboss.deployment.unit.\"EntitiesProject.jar\".weld.weldClassIntrospector is missing [jboss.deployment.unit.\"EntitiesProject.jar\".beanmanager]",
    "jboss.naming.context.java.comp.EntitiesProject.EntitiesProject.MitarbeiterDAO.HandleDelegate is missing [jboss.naming.context.java.comp.EntitiesProject.EntitiesProject.MitarbeiterDAO]",
    "jboss.naming.context.java.comp.EntitiesProject.EntitiesProject.MitarbeiterDAO.InstanceName is missing [jboss.naming.context.java.comp.EntitiesProject.EntitiesProject.MitarbeiterDAO]",
    "jboss.naming.context.java.comp.EntitiesProject.EntitiesProject.MitarbeiterDAO.InAppClientContainer is missing [jboss.naming.context.java.comp.EntitiesProject.EntitiesProject.MitarbeiterDAO]",
    "jboss.naming.context.java.comp.EntitiesProject.EntitiesProject.MitarbeiterDAO.Validator is missing [jboss.naming.context.java.comp.EntitiesProject.EntitiesProject.MitarbeiterDAO]",
    "jboss.naming.context.java.comp.EntitiesProject.EntitiesProject.MitarbeiterDAO.ORB is missing [jboss.naming.context.java.comp.EntitiesProject.EntitiesProject.MitarbeiterDAO]",
    "jboss.naming.context.java.comp.EntitiesProject.EntitiesProject.MitarbeiterDAO.ValidatorFactory is missing [jboss.naming.context.java.comp.EntitiesProject.EntitiesProject.MitarbeiterDAO]"
]

这是我的SessionBean，我尝试注入EntityManager：

@Stateless
public class MitarbeiterDAO implements MitarbeiterDAORemote {

    @PersistenceContext
    private EntityManager em;

    public int writeMitarbeiterToDB(Mitarbeiter m)
    {
        em.persist(m);
        return m.getId();
    }
}

我已经指定了以下文件，我将其放入“项目名称”/ejbModule/META-INF。persistence.xml

<persistence-unit name="mitarbeiter">
   <provider>org.hibernate.ejb.HibernatePersistence</provider>
      <jta-data-source>java:jboss/datasources/MySqlDS</jta-data-source>
   <properties>
      <property-name="hibernate.hbm2ddl.auto" value="create-drop"/>
   </properties>
</persistence-unit>

类似问题及其解决方案

找不到持久性单元建议包含持久性.xml
注入实体管理器在Wildfly / Jboss指出，我的持久性.xml可能属于另一个目录。我尝试了该目录，但仍然收到相同的错误消息。
无法从持久性中找到持久性单元.xml虽然这不是完全相同的问题，但解决方案是为持久性添加一个.xml，但这对我也不起作用。<provider>

更新（见评论）：
- 我试图使用而不是仅仅 - 上面显示的会话豆是我尝试注入的唯一地方@EntityManager(unitName="mitarbeiter")@EntityManagerEntityManager

更新2（见答案的评论）：

persistence.xml在目录中Project/ejbModule/META-INF/
此目录包含在构建路径中
不知何故，当同一目录中的其他文件（到）时，它没有得到部署。如果我手动复制并粘贴它，它可以工作。为什么？jar/META-INF/

任何帮助和提示都非常感谢。

答案 1

几个可能的问题：

文件位置不正确。请将其放在存档根目录下的目录中。如果你使用maven，它将是.persistence.xmlMETA-INF/src/main/resources/META-INF/persistence.xml
文件无效：您已将标记在行中关闭（请注意在末尾）persistence.xmlpersistence-unit<persistence-unit name="mitarbeiter"/>/
<property-name="hibernate.hbm2ddl.auto" value="create-drop"/>无效。我想你想要：<property name="hibernate.hbm2ddl.auto" value="create-drop" />
此外，您正在使用的提供程序已弃用。

通常，在您的案例中，JPA 2.1 的正确内容应如下所示：persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence 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"
  version="2.1">

  <persistence-unit name="mitarbeiter">
    <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
    <jta-data-source>java:jboss/datasources/MySqlDS</jta-data-source>

    <properties>
      <property name="hibernate.hbm2ddl.auto" value="create-drop" />
    </properties>
  </persistence-unit>
</persistence>

答案 2

我已经追了几个星期的这个问题。我在MassiveGrid（一个托管的服务器环境）上使用Wildfly 20，AdoptOpenJDK 14，Maven和MySql。最终对我有用的是我在JBoss上找到的一篇文章，它解决了我的问题。我的测试环境是Windows 10，无需修复即可正常工作。解决方案结果是在Web Pages/META-INF命名服务下添加一个文件夹，并放置一个名为java.sql.Driver的文件，其中包含以下内容：

<?xml version="1.0" encoding="UTF-8"?>

<!--
  ~ JBoss, Home of Professional Open Source.
  ~ Copyright 2010, Red Hat, Inc., and individual contributors
  ~ as indicated by the @author tags. See the copyright.txt file in the
  ~ distribution for a full listing of individual contributors.
  ~
  ~ This is free software; you can redistribute it and/or modify it
  ~ under the terms of the GNU Lesser General Public License as
  ~ published by the Free Software Foundation; either version 2.1 of
  ~ the License, or (at your option) any later version.
  ~
  ~ This software is distributed in the hope that it will be useful,
  ~ but WITHOUT ANY WARRANTY; without even the implied warranty of
  ~ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  ~ Lesser General Public License for more details.
  ~
  ~ You should have received a copy of the GNU Lesser General Public
  ~ License along with this software; if not, write to the Free
  ~ Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  ~ 02110-1301 USA, or see the FSF site: http://www.fsf.org.
  -->

<module xmlns="urn:jboss:module:1.0" name="com.mysql">
  <resources>
    <resource-root path="mysql-connector-java-8.0.18.jar"/>
  </resources>
  <dependencies>
    <module name="javax.api"/>
  </dependencies>
</module>