Help with IllegalArgumentException: Object: ... is not a known entity type.

Question

Hi there.
I'm trying to get TopLink JPA running with Oracle / Spring / JUnit, but so far with no success. The exception I get when trying to persist my rather simple entity is :
java.lang.IllegalArgumentException: Object: com.yospace.tundra.mediafarm.job.Job@38b554 is not a known entity type.
     at oracle.toplink.essentials.internal.sessions.UnitOfWorkImpl.registerNewObjectForPersist(UnitOfWorkImpl.java:3198)
     at oracle.toplink.essentials.internal.ejb.cmp3.base.EntityManagerImpl.persist(EntityManagerImpl.java:190)
My entity class is :
package com.yospace.tundra.mediafarm.job;
// imports ...
@Entity()
public class Job
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
public Job()
* @return the id
public Long getId()
return id;
* Set the id of this job.
* @param id
public void setId(Long id)
this.id = id;
My persistence.xml is :
<persistence 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 persistence_1_0.xsd" version="1.0">
<persistence-unit name="TundraPu" transaction-type="RESOURCE_LOCAL">
<provider>
oracle.toplink.essentials.PersistenceProvider
</provider>
          <!-- List all entity classes here. -->
     <class>com.yospace.tundra.mediafarm.job.Job</class>
<properties>
<property name="toplink.logging.level" value="FINE"/>
</properties>
</persistence-unit>
</persistence>
My spring.xml is :
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns:aop="http://www.springframework.org/schema/aop"
     xmlns:tx="http://www.springframework.org/schema/tx"
     xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
     http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd">
<bean id="jobDao" class="com.yospace.tundra.mediafarm.job.JobDao">
</bean>
     <!-- Location of test database configuration. -->
     <bean id="propertyConfigurer"
          class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
          <property name="locations">
               <list>
                    <value>/test/resources/jdbc.properties</value>
               </list>
          </property>
     </bean>
     <bean id="dataSource"
          class="org.springframework.jdbc.datasource.DriverManagerDataSource">
          <property name="driverClassName"
               value="${jdbc.driverClassName}" />
          <property name="url" value="${jdbc.url}" />
          <property name="username" value="${jdbc.username}" />
          <property name="password" value="${jdbc.password}" />
     </bean>
     <!-- Toplink JPA entity manager configuration. -->
     <bean id="loadTimeWeaver" class="org.springframework.instrument.classloading.SimpleLoadTimeWeaver"/>
     <bean id="entityManagerFactory"
          class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
          <property name="dataSource" ref="dataSource" />
          <property name="jpaVendorAdapter">
               <bean
                    class="org.springframework.orm.jpa.vendor.TopLinkJpaVendorAdapter">
                    <property name="databasePlatform"
                         value="${jpavendor.dialect}" />
                    <property name="generateDdl" value="true" />
                    <property name="showSql" value="true" />
               </bean>
          </property>
          <property name="loadTimeWeaver" ref="loadTimeWeaver"/>
     </bean>
     <bean
          class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />
     <!-- JPA transaction manager configuration. -->
          <bean id="transactionManager"
          class="org.springframework.orm.jpa.JpaTransactionManager">
          <property name="entityManagerFactory"
          ref="entityManagerFactory" />
          </bean>
     <tx:annotation-driven transaction-manager="transactionManager" />
</beans>
This fails when I run a JUnit test under Eclipse -- it falls over on the first operation, which creates then attempts to persist a job.
I wonder if anyone has any ideas as to what exactly I'm doing wrong ...?
Thanks,
Henry

Answer 1

I had the same "is not a known entity type" error when running under a development environment Eclipse/Tomcat using Toplink. But the almost same code and configuration worked when running under Eclipse as a stand-alone Java app.
Eventually I figured out (actually trial and error), that I had checked the toplink-essentials.jar libraries to be exported under: Eclipse Project/Java Build Path/Order and Export. I was messing around with libraries. Unchecking the export option there fixed the problem.
While its unlikely that this could have been your exact problem, I would check the library order and export configurations. Looking at other message boards about this problem, many seemed to have been caused or fixed by playing with their libraries.