What is "object is not an instance of declaring class" error in hibernate?

[vighnesh udupa]

Hi,

Can anybody help me resolving the following error?

org.hibernate.PropertyAccessException: IllegalArgumentException occurred calling getter of com.ART.vo.ART_EmployeeVO.EmployeeID
	at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:195)
	at org.hibernate.tuple.entity.AbstractEntityTuplizer.getIdentifier(AbstractEntityTuplizer.java:206)
	at org.hibernate.persister.entity.AbstractEntityPersister.getIdentifier(AbstractEntityPersister.java:3619)
	at org.hibernate.persister.entity.AbstractEntityPersister.isTransient(AbstractEntityPersister.java:3335)
	at org.hibernate.engine.ForeignKeys.isTransient(ForeignKeys.java:204)
	at org.hibernate.event.def.AbstractSaveEventListener.getEntityState(AbstractSaveEventListener.java:535)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:103)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93)
	at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:534)
	at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:526)
	at org.hibernate.engine.CascadingAction$5.cascade(CascadingAction.java:241)
	at org.hibernate.engine.Cascade.cascadeToOne(Cascade.java:291)
	at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:239)
	at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:192)
	at org.hibernate.engine.Cascade.cascade(Cascade.java:153)
	at org.hibernate.event.def.AbstractSaveEventListener.cascadeBeforeSave(AbstractSaveEventListener.java:454)
	at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:288)
	at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:204)
	at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:144)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:210)
	at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:56)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:195)
	at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:50)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93)
	at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:562)
	at org.hibernate.impl.SessionImpl.save(SessionImpl.java:550)
	at org.hibernate.impl.SessionImpl.save(SessionImpl.java:546)
	at com.ART.dao.ART_ProjectDAO.addProjectDetails(ART_ProjectDAO.java:70)
	at com.ART.bo.ART_ProjectBO.addProjectDetails(ART_ProjectBO.java:30)
	at com.ART.action.ART_Action.addProjectDetails(ART_Action.java:282)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:440)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
	at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.IllegalArgumentException: object is not an instance of declaring class
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:169)
	... 99 more

I removed some line of error message stack as it is too big to put here.

My hibernate mapping file :-

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
	<class name="com.ART.vo.ART_ProjectVO" table="ART_ProjectTab">
		<id name="projectID" column="ProjectID" />
		<property name="projectName" column="ProjectName" />
		<property name="projectDescription" column="ProjectDescription" />
		<property name="projectType" column="ProjectType" />
		<property name="projectAlias" column="ProjectAlias" />
		<property name="projectStartDate" type="timestamp" column="ProjectStartDate" />
		<property name="projectEndDate" type="timestamp" column="ProjectEndDate" />
		<property name="deleteFlag" column="DeleteFlag" />

		<many-to-one name="projectManager" class="com.ART.vo.ART_EmployeeVO"
			column="EmployeeID" cascade="all" />
	</class>
	</hibernate-mapping>

where project manager is a foreign key in ART_ProjectTab table and primary key in ART_EmployeeTab table.

When I try to add the project details to DB i am getting the following error. I tried in web also but didn't get enough information to resolve the issue.

Thanks,
Vighnesh

[Reddy Prashanth]

Can you paste the source code for the two java classes as well ( ART_ProjectVO and ART_EmployeeVO).

[chetan agg]

hi,

i am facing same problem. Can you tell me how you solved this problem?

Thanks
Chetan