Websphere: JPA: java.lang.IllegalArgumentException: Object: Entity is not a known entity type

I'm trying to deploy an app using Eclipselink as my JPA Layer on IBM Websphere 7.0.0.9. While trying to do any CRUD operations, i get the following exception:

Caused by: java.lang.IllegalArgumentException: Object: Entity is not a known entity type.
 at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNewObjectForPersist(UnitOfWorkImpl.java:4199)
 at org.eclipse.persistence.internal.jpa.EntityManagerImpl.persist(EntityManagerImpl.java:380)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
 at java.lang.reflect.Method.invoke(Method.java:600)
 at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:358)
 at $Proxy93.persist(Unknown Source)
 ... 89 more

Another stack trace i see is :

Caused by: java.lang.ClassCastException: Entity incompatible with Entity
    at o.u.d.dao.jpa.converter.impl.EntityBeanConvertorImpl.convertToModel(EntityBeanConvertorImpl.java:143)
    ... 223 more

My persistence.xml looks like:

     <persistence-unit name="ds" transaction-type="JTA">   <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>      <jta-data-source>dsjta</jta-data-source>   <class>Entity</class>      <exclude-unlisted-classes>true</exclude-unlisted-classes>     <properties>    <property name="eclipselink.target-server" value="WebSphere_7" />    <property name="eclipselink.logging.level" value="OFF" /> 开发者_JS百科   <property name="eclipselink.ddl-generation" value="none" />    <property name="eclipselink.ddl-generation.output-mode" value="database" />    </properties>  </persistence-unit>

My application context file looks like:

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">    <property name="persistenceUnitName" value="ds"/>  <property name="dataSource" ref="dataSource"/>  <property name="jpaVendorAdapter">   <bean class="org.springframework.orm.jpa.vendor.EclipseLinkJpaVendorAdapter">    <property name="showSql" value="false"/>    <property name="generateDdl" value="false"/>   </bean>  </property>  <property name="loadTimeWeaver">   <bean class="org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver"/>  </property>   </bean>

Our VM is started with the -javaagent parameter specified and pointing to spring-agent.jar What could be the reason for these exceptions?

The issue here is there is no Spring LoadTimeWeaver for Websphere. When your application attempts to combine a Web-Tier application with the Spring managed EM while using the InstrumentationLoadTimeWeaver class cast exceptions result. EclipseLink supports weaving in all JPA 2 compliant containers but in this case Spring is acting as an intermediary and interfering with the weaving.

Until Spring has a LoadTimeWeaver for Websphere You will need to remove the InstrumentationLoadTimeWeaver and set the EclipseLink persistence.xml property "eclipselink.weaving" to false or use the Static weaver.