Hi , i'm new on this forum , i really spent a lot of time searching the web
why i can't define a class which is defined in function of a generic type.
To make the concept clear i have the class Broker defined as follows

@Entity
@DiscriminatorColumn(name="Type")
public abstract class Broker<M extends AbstractEntity, I extends Item>
{
@Id@GeneratedValue(strategy=GenerationType.AUTO)
private Integer id;
@ManyToOne
private M master;
@Transient
protected I detail;
private Integer detail_id;
public Broker()
{
}
public Broker(M contenitore, I contenuto)
{
this.master = contenitore;
setDetail(contenuto);
}
public Integer getId()
{
return id;
}
public void setId(Integer idDetails)
{
this.id = idDetails;
}
public M getMaster()
{
return master;
}
public void setMaster(M beta)
{
this.master = beta;
}
@SuppressWarnings("unchecked")
@Transient
public I getDetail() {
if (detail == null)
{
EntityManager em = JPAContext.entityManager();
detail = (I)em.find(getDetailClass(),this.getDetailId());
}
return detail;
}
@Transient
public synchronized void setDetail(I detail) {
this.detail = detail;
this.detail_id = detail.getId();
}
protected Integer getDetailId()
{
return detail_id;
}
protected abstract Class<?> getDetailClass()
;
}

javax.persistence.PersistenceException: org.hibernate.AnnotationException:

Property it.cspnet.jpa.Broker.master has an unbound type and no explicit target entity. Resolve this Generic usage issue or set an explicit target attribute (eg @OneToMany(target=) or use an explicit @Type


and here is the stack trace in case it could be useful

at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:258)
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:120)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:51)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:33)
at it.cspnet.jpa.TestScritturaBeta.inizializzaEntityManager(TestScritturaBeta.java:212)
at it.cspnet.jpa.TestScritturaBeta.setUp(TestScritturaBeta.java:41)
at junit.framework.TestCase.runBare(TestCase.java:132)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)
at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:124)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at org.junit.internal.runners.OldTestClassRunner.run(OldTestClassRunner.java:76)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:38)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
Caused by: org.hibernate.AnnotationException: Property it.cspnet.jpa.Broker.master has an unbound type and no explicit target entity. Resolve this Generic usage issue or set an explicit target attribute (eg @OneToMany(target=) or use an explicit @Type
at org.hibernate.cfg.AnnotationBinder.addElementsOfAClass(AnnotationBinder.java:993)
at org.hibernate.cfg.AnnotationBinder.getElementsToProcess(AnnotationBinder.java:833)
at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:645)
at org.hibernate.cfg.AnnotationConfiguration.processArtifactsOfType(AnnotationConfiguration.java:498)
at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:277)
at org.hibernate.cfg.Configuration.buildMappings(Configuration.java:1115)
at org.hibernate.ejb.Ejb3Configuration.buildMappings(Ejb3Configuration.java:1269)
at org.hibernate.ejb.EventListenerConfigurator.configure(EventListenerConfigurator.java:150)
at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:888)
at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:186)
at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:246)
... 19 more

What's the matter with that ?
Should i remove generics in the definition of the signature of the class?
How are generics managed by the persistence framework ?
Please help , i need to solve the problem or at least to have some advice
on how to fix it if it is possible and if it is not possible i would like to know so i can give up using it [/b]