希望我能正确解释这个问题。我有 3 个类处理我的实体。
@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)
我正在使用附带的 glassfish 版本运行 netbeans 6.1。mysql 5.0。