JPA - 未知的实体bean类

Question

希望我能正确解释这个问题.我有3个课程来处理我的实体.

@MappedSuperclass
public abstract class Swab implements ISwab {
...
    private Collection<SwabAccounts> accounts;
...
}

@Entity
@Table(name="switches")
@DiscriminatorColumn(name="type")
@DiscriminatorValue(value="DMS500")
public class DmsSwab extends Swab implements ISwab, Serializable {
...
    private ObjectPool pool;
...
    @Transient 
    public ObjectPool getPool(){
        return pool;
    }
...
}

@Entity(name="swab_accounts")
public class SwabAccounts implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int swab_account_id;
    private int swab_id;
...
}

在EJB中,查询正在以这种方式进行

    DmsSwab dms = em.find(DmsSwab.class, 2);
    List<Swab> s = new ArrayList<Swab>(1);
    s.add(dms);

我的persistence.xml看起来像这样:

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" 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_1_0.xsd">
  <persistence-unit name="dflow-pu" transaction-type="RESOURCE_LOCAL">
    <provider>oracle.toplink.essentials.PersistenceProvider</provider>
    <class>com.dcom.sap.dms.DmsSwab</class>
    <class>com.dcom.sap.jpa.SwabAccounts</class>
    <properties>
      <property name="toplink.jdbc.user" value="dflow"/>
      <property name="toplink.jdbc.password" value="dflow"/>
      <property name="toplink.jdbc.url" value="jdbc:mysql://itcd-400447:3306/dflow"/>
      <property name="toplink.jdbc.driver" value="com.mysql.jdbc.Driver"/>
    </properties>
  </persistence-unit>
</persistence>

我收到此错误:

java.lang.IllegalArgumentException: Unknown entity bean class: class com.dcom.sap.dms.DmsSwab, please verify that this class has been marked with the @Entity annotation.
com.dcom.sap.SwabException: java.lang.IllegalArgumentException: Unknown entity bean class: class com.dcom.sap.dms.DmsSwab, please verify that this class has been marked with the @Entity annotation.
Caused by: java.lang.IllegalArgumentException: Unknown entity bean class: class com.dcom.sap.dms.DmsSwab, please verify that this class has been marked with the @Entity annotation.
        at oracle.toplink.essentials.internal.ejb.cmp3.base.EntityManagerImpl.findInternal(EntityManagerImpl.java:306)
        at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerImpl.find(EntityManagerImpl.java:148)

我正在使用随附的glassfish版本运行netbeans 6.1.MySql 5.0.

Answer 1

在persistence.xml中的class标签中定义此实体

Answer 2

根据错误消息和我从你的代码中得出的结果，错误似乎在 persistence.xml 文件中，你能更详细一点吗？