Hello, i have a problem when using generics type parameters for entity properties.
when i have a
@Entity
class X<E> {
@Basic
E getValue();
}
hibernate tries to somehow discover the actual type for the parameter.
It didn't work this way in hib-anno 3.1beta6 and does not work this way for mapped fields.
is this behavior (apart the nullpointer) correct? and is the below mentioned mapping correct?


Hibernate version:
hibernate 3.1.1
hibernate-annotations 3.1beta8
hibernate-entitymanager 3.1beta6

Mapping documents:
@Entity
@Inheritance (strategy = InheritanceType.SINGLE_TABLE)
@SequenceGenerator (name = "Generator", sequenceName = "hibernate_seq")
public abstract class TestTopClass<Test extends TestHelpClass> {
private long id;
private Test test;

@Id
@GeneratedValue (generator = "Generator", strategy = GenerationType.AUTO)
public long getId() {
return id;
}

public void setId(long id) {
this.id = id;
}

@OneToOne
public Test getTest() {
return test;
}

public void setTest(Test test) {
this.test = test;
}
}

@Entity
public class TestMiddleClass extends TestTopClass<TestHelpClass> {

}

@Entity
public class TestHelpClass {
@Id
private long id;
}

Full stack trace of any exception that occurs:
java.lang.NullPointerException
at org.hibernate.cfg.PropertyInferredData.extractType(PropertyInferredData.java:212)
at org.hibernate.cfg.PropertyInferredData.execute(PropertyInferredData.java:124)
at org.hibernate.cfg.PropertyInferredData.skip(PropertyInferredData.java:60)
at org.hibernate.cfg.AnnotationBinder.addAnnotatedElement(AnnotationBinder.java:900)
at org.hibernate.cfg.AnnotationBinder.addElementsOfAClass(AnnotationBinder.java:868)
at org.hibernate.cfg.AnnotationBinder.getElementsToProcess(AnnotationBinder.java:717)
at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:547)
at org.hibernate.cfg.AnnotationConfiguration.processArtifactsOfType(AnnotationConfiguration.java:276)
at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:210)
at org.hibernate.cfg.Configuration.buildMappings(Configuration.java:996)
at org.hibernate.ejb.Ejb3Configuration.buildMappings(Ejb3Configuration.java:722)
at org.hibernate.ejb.EventListenerConfigurator.configure(EventListenerConfigurator.java:161)
at org.hibernate.ejb.Ejb3Configuration.createEntityManagerFactory(Ejb3Configuration.java:567)
at org.hibernate.ejb.Ejb3Configuration.createContainerEntityManagerFactory(Ejb3Configuration.java:245)
at cz.eurotel.persistencehibernate.ResourceBasedSessionManager.initializeResource(ResourceBasedSessionManager.java:74)

Debug level Hibernate log excerpt:
TEST 2006-01-24T13:01:03.171 INFO [TestTask] org.hibernate.ejb.Ejb3Configuration - found EJB3 Entity bean: test.persistence.hibernate.TestHelpClass
TEST 2006-01-24T13:01:03.171 INFO [TestTask] org.hibernate.ejb.Ejb3Configuration - found EJB3 Entity bean: test.persistence.hibernate.TestMiddleClass
TEST 2006-01-24T13:01:03.187 INFO [TestTask] org.hibernate.ejb.Ejb3Configuration - found EJB3 Entity bean: test.persistence.hibernate.TestTopClass
TEST 2006-01-24T13:01:03.421 DEBUG [TestTask] org.hibernate.cfg.AnnotationConfiguration - Execute first pass mapping processing
TEST 2006-01-24T13:01:03.421 DEBUG [TestTask] org.hibernate.cfg.AnnotationConfiguration - Process hbm files
TEST 2006-01-24T13:01:03.421 DEBUG [TestTask] org.hibernate.cfg.AnnotationConfiguration - Process annotated classes
TEST 2006-01-24T13:01:03.515 INFO [TestTask] org.hibernate.cfg.AnnotationBinder - Binding entity from annotated class: test.persistence.hibernate.TestHelpClass
TEST 2006-01-24T13:01:03.546 DEBUG [TestTask] org.hibernate.cfg.Ejb3Column - Binding column TYPE unique false
TEST 2006-01-24T13:01:03.593 DEBUG [TestTask] org.hibernate.cfg.annotations.EntityBinder - Import with entity name=TestHelpClass
TEST 2006-01-24T13:01:03.609 INFO [TestTask] org.hibernate.cfg.annotations.EntityBinder - Bind entity test.persistence.hibernate.TestHelpClass on table TestHelpClass
TEST 2006-01-24T13:01:07.406 DEBUG [TestTask] org.hibernate.cfg.AnnotationBinder - Processing test.persistence.hibernate.TestHelpClass per property annotation
TEST 2006-01-24T13:01:07.406 DEBUG [TestTask] org.hibernate.cfg.AnnotationBinder - Processing test.persistence.hibernate.TestHelpClass per field annotation
TEST 2006-01-24T13:01:09.046 DEBUG [TestTask] org.hibernate.cfg.AnnotationBinder - Processing annotations of test.persistence.hibernate.TestHelpClass.id
TEST 2006-01-24T13:01:09.062 DEBUG [TestTask] org.hibernate.cfg.Ejb3Column - Binding column id unique false
TEST 2006-01-24T13:01:09.062 DEBUG [TestTask] org.hibernate.cfg.AnnotationBinder - id is an id
TEST 2006-01-24T13:01:09.062 DEBUG [TestTask] org.hibernate.cfg.annotations.SimpleValueBinder - building SimpleValue for id
TEST 2006-01-24T13:01:09.078 DEBUG [TestTask] org.hibernate.cfg.annotations.PropertyBinder - Building property id
TEST 2006-01-24T13:01:09.078 DEBUG [TestTask] org.hibernate.cfg.annotations.PropertyBinder - Cascading id with null
TEST 2006-01-24T13:01:09.078 DEBUG [TestTask] org.hibernate.cfg.AnnotationBinder - Bind @Id on id
TEST 2006-01-24T13:01:09.093 DEBUG [TestTask] org.hibernate.validator.ClassValidator - ResourceBundle ValidatorMessages not found. Delegate to org.hibernate.validator.resources.DefaultValida
torMessages
TEST 2006-01-24T13:01:09.093 INFO [TestTask] org.hibernate.cfg.AnnotationBinder - Binding entity from annotated class: test.persistence.hibernate.TestTopClass
TEST 2006-01-24T13:01:09.093 DEBUG [TestTask] org.hibernate.cfg.Ejb3Column - Binding column TYPE unique false
TEST 2006-01-24T13:01:09.093 DEBUG [TestTask] org.hibernate.cfg.annotations.EntityBinder - Import with entity name=TestTopClass
TEST 2006-01-24T13:01:09.093 INFO [TestTask] org.hibernate.cfg.annotations.EntityBinder - Bind entity test.persistence.hibernate.TestTopClass on table TestTopClass
TEST 2006-01-24T13:01:09.093 DEBUG [TestTask] org.hibernate.cfg.AnnotationBinder - Setting discriminator for entity test.persistence.hibernate.TestTopClass
TEST 2006-01-24T13:01:09.109 DEBUG [TestTask] org.hibernate.cfg.AnnotationBinder - Add sequence generator with name: Generator
TEST 2006-01-24T13:01:11.406 DEBUG [TestTask] org.hibernate.cfg.AnnotationBinder - Processing test.persistence.hibernate.TestTopClass per property annotation
TEST 2006-01-24T13:03:49.656 DEBUG [TestTask] sw.objects.TestTask - test HibernateTest crashed
java.lang.NullPointerException
at org.hibernate.cfg.PropertyInferredData.extractType(PropertyInferredData.java:212)
at org.hibernate.cfg.PropertyInferredData.execute(PropertyInferredData.java:124)
at org.hibernate.cfg.PropertyInferredData.skip(PropertyInferredData.java:60)
at org.hibernate.cfg.AnnotationBinder.addAnnotatedElement(AnnotationBinder.java:900)
at org.hibernate.cfg.AnnotationBinder.addElementsOfAClass(AnnotationBinder.java:868)
at org.hibernate.cfg.AnnotationBinder.getElementsToProcess(AnnotationBinder.java:717)
at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:547)
at org.hibernate.cfg.AnnotationConfiguration.processArtifactsOfType(AnnotationConfiguration.java:276)
at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:210)
at org.hibernate.cfg.Configuration.buildMappings(Configuration.java:996)
at org.hibernate.ejb.Ejb3Configuration.buildMappings(Ejb3Configuration.java:722)
at org.hibernate.ejb.EventListenerConfigurator.configure(EventListenerConfigurator.java:161)
at org.hibernate.ejb.Ejb3Configuration.createEntityManagerFactory(Ejb3Configuration.java:567)
at org.hibernate.ejb.Ejb3Configuration.createContainerEntityManagerFactory(Ejb3Configuration.java:245)
at cz.eurotel.persistencehibernate.ResourceBasedSessionManager.initializeResource(ResourceBasedSessionManager.java:74)

Open a case on that, but I don't think it makes sense in ORM to map such a structure. We might want to avoid issue if targetEntity is explicitly defined though

Was there an issue opened for this at all?

I have the same problem, and found an Issue at http://opensource2.atlassian.com/projec ... se/ANN-181 .