JPA - Unknown entity bean class

Question

Hopefully, I can explain this issue properly. I have 3 classes that deals with my entities.

@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;
...
}

And in a EJB a query is being doing this way

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

My persistence.xml looks like this:

<?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>

I get this error:

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)

I am running netbeans 6.1 with the version of glassfish that comes with it. MySql 5.0.

Answer 1

在persistence.xml中的class标签中定义这个实体

Answer 2

根据错误消息和我从您的代码中得出的结论，错误似乎在persistence.xml 文件中，您能说得更详细一点吗？

Answer 3

I had the same error and, complementing the information above, my case was a ClassLoader issue. My app has three files. A ejb-module.jar which depends on app-lib.jar (library that contains pojo and database entities) and a web-module.war which depends on app-lib.jar.

In the deployment, the app-lib.jar was loaded twice by the glassfish. Googling, I found out that I should copy the app-lib.jar to a "shared" lib in the glassfish domain. I've copied the postgresql.jar to "domain-dir/lib" and my app-lib.jar to "domain-dir/lib/applibs". Have it done, the app worked like a charm.

The used explanation can be found here: http://docs.oracle.com/cd/E19798-01/821-1752/beade/index.html

Answer 4

I solved this issue creating a ContextListener in to my Web App, invoking the close of the entity manager factory at destroy context, :

public void contextDestroyed(ServletContextEvent servletContextEvent) {
    try {
        logger.info("contextDestroyed...");
        LifeCycleManager lifeCycleManager = ServiceLocator.getLifeCycleManager();
        lifeCycleManager.closeEntityManagerFactory();

    } catch (Exception e) {
        logger.error(e.getMessage(), e);
    }
}

I also create a bean with name LifeCycleManager and inside them invoke a DAO method to close the entity manager factory:

public void closeEntityManagerFactory() throws BusinessException {
        logger.info("closeEntityManager");
        try {
            logger.info("closing entity manager factory...");
            genericDAO.closeEntityManagerFactory();
            logger.info("Entity manager factiry closed");
        } catch (Exception e) {
            throw new BusinessException(BusinessErrorCode.CODIGO_EJEMPLO_01, Severity.ERROR);
        }
    }

Inside the DAO:

...

@Autowired
private EntityManagerFactory entityManagerFactory;

...

public void closeEntityManagerFactory() {
        logger.info("closing entity manager factory");
        getEntityManagerFactory().close();
        logger.info("entity manager factory closed");   
    }

Using this each time I deploy a change from my eclipse environment the destroy context is invoked. I hope could help you guys, my environment is WebLogic Server 11gR1 and JPA 1.0.

Answer 5

Mario was right when he mentions EntityManagerFactory here.

Both:

java.lang.IllegalArgumentException : Unknown entity bean class...

and

java.lang.IllegalStateException : This web container has not yet been started...

These exceptions occur when you redeploy a web application multiple times but didn't close EntityManagerFactory properly.

follow this instruction to register ServletContextListener and this instruction to close EntityManagerFactory properly.