Hi. I've been having a trouble figureing out what I did wrong with the getter. I have a one to many relationship between table Company and CompanyListing. Company has companyId(PK), name. I'm trying to have CompanyListing associated with Comapny by using FK companyId. If anyone can give me any tips how to solve this problem, I would appreciate it very much.

Hibernate version:3.0

Mapping documents:
<?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
package="com.adsmack.framework.domain">

<class name="Company" table = "company">
<id name="companyId">
<generator class="native"/>
</id>
<property name="name"/>
<set name = "companyListingList" inverse = "true" lazy = "true">
<key column = "companyId"/>
<one-to-many class = "CompanyListing"/>
</set>
</class>

<class name="CompanyListing" table = "companylisting">
<id name="id" column = "id">
<generator class="native"/>
</id>
<property name="displayName"/>
<property name="pictureURL"/>
<property name="websiteURL"/>
<property name="companyEmail"/>
<property name="shortDescription"/>
<property name="longDescription"/>

<many-to-one name = "companyId" class = "Company" column = "companyId"/>
<bag name = "companyCategoryList" table = "companycategory_companylisting">
<key column = "CompanyListingId" />
<many-to-many class = "CompanyCategory" column = "CompanyCategoryId"/>
</bag>
</class>

<class name="CompanyCategory" table = "companycategory">
<id name="id" column = "id">
<generator class="native"/>
</id>
<property name="categoryName1"/>
<property name="categoryName2"/>
<property name="categoryName3"/>
</class>

</hibernate-mapping>

Code between sessionFactory.openSession() and session.close():
Session s = factory.openSession();
Transaction tx = s.beginTransaction();

Long generatedID = (Long) s.save(theCompanyListing);
theCompanyListing.setId(generatedID);
tx.commit();

Full stack trace of any exception that occurs:
org.hibernate.PropertyAccessException: IllegalArgumentException occurred calling getter of com.adsmack.framework.domain.Company.companyId
at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:119)
at org.hibernate.tuple.AbstractTuplizer.getIdentifier(AbstractTuplizer.java:103)
at org.hibernate.persister.entity.BasicEntityPersister.getIdentifier(BasicEntityPersister.java:2947)
at org.hibernate.persister.entity.BasicEntityPersister.isTransient(BasicEntityPersister.java:2724)
at org.hibernate.engine.ForeignKeys.isTransient(ForeignKeys.java:175)
at org.hibernate.engine.ForeignKeys$Nullifier.isNullifiable(ForeignKeys.java:137)
at org.hibernate.engine.ForeignKeys$Nullifier.nullifyTransientReferences(ForeignKeys.java:69)
at org.hibernate.engine.ForeignKeys$Nullifier.nullifyTransientReferences(ForeignKeys.java:47)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:232)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:158)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:104)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:184)
at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:173)
at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:69)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:429)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:424)
at com.adsmack.framework.persistence.hibernateDAO.HibernateCompanyDAO.createCompanyListing(HibernateCompanyDAO.java:109)
at com.adsmack.framework.business.helpers.CompanyHelper.createCompanyListing(CompanyHelper.java:117)
at com.adsmack.framework.persistence.TestCompanyHelper.testCreateCompanyListing(TestCompanyHelper.java:47)
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 junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at junit.framework.TestSuite.runTest(TestSuite.java:208)
at junit.framework.TestSuite.run(TestSuite.java:203)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:436)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:311)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: java.lang.IllegalArgumentException: object is not an instance of declaring class
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:105)
... 35 more



Name and version of the database you are using:MySQL 4.1.12

PropertyAccessException can be caused because of many reason. Some are
1) Type Casting
2) Null field in the DB assigned to a primitive type.

Check the JavaDoc for this error you may get more info.
http://www.hibernate.org/hib_docs/v3/api/org/hibernate/PropertyAccessException.html