Hi,
I have a problem with a simple form of my Seam project.
When I submit the form I have this error:

ERROR [TxPolicy] javax.ejb.EJBTransactionRolledbackException: attempt to create create event with null entity
12:38:29,923 SEVERE [application] javax.ejb.EJBTransactionRolledbackException: attempt to create create event with null entity
javax.faces.el.EvaluationException: javax.ejb.EJBTransactionRolledbackException: attempt to create create event with null entity
        at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:102)
        at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
        at javax.faces.component.UICommand.broadcast(UICommand.java:387)
        at org.ajax4jsf.component.AjaxViewRoot.processEvents(AjaxViewRoot.java:321)
        at org.ajax4jsf.component.AjaxViewRoot.broadcastEvents(AjaxViewRoot.java:296)
        at org.ajax4jsf.component.AjaxViewRoot.processPhase(AjaxViewRoot.java:253)
        at org.ajax4jsf.component.AjaxViewRoot.processApplication(AjaxViewRoot.java:466)
        at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:82)
        at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
        at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
        at javax.faces.webapp.FacesServlet.service(FacesServlet.java:265)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
        at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178)
        at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
        at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:368)
        at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:495)
        at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.jboss.seam.web.HotDeployFilter.doFilter(HotDeployFilter.java:53)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:235)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
        at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:190)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433)
        at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:92)
        at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.process(SecurityContextEstablishmentValve.java:126)
        at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:70)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:330)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:829)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:598)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
        at java.lang.Thread.run(Unknown Source)
Caused by: javax.ejb.EJBTransactionRolledbackException: attempt to create create event with null entity
        at org.jboss.ejb3.tx.Ejb3TxPolicy.handleInCallerTx(Ejb3TxPolicy.java:115)
        at org.jboss.aspects.tx.TxPolicy.invokeInCallerTx(TxPolicy.java:130)
        at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:194)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:76)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.tx.NullInterceptor.invoke(NullInterceptor.java:42)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.security.RoleBasedAuthorizationInterceptorv2.invoke(RoleBasedAuthorizationInterceptorv2.java:201)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.security.Ejb3AuthenticationInterceptorv2.invoke(Ejb3AuthenticationInterceptorv2.java:186)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:41)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.BlockContainerShutdownInterceptor.invoke(BlockContainerShutdownInterceptor.java:67)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.aspects.currentinvocation.CurrentInvocationInterceptor.invoke(CurrentInvocationInterceptor.java:67)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.session.SessionSpecContainer.invoke(SessionSpecContainer.java:176)
        at org.jboss.ejb3.session.SessionSpecContainer.invoke(SessionSpecContainer.java:216)
        at org.jboss.ejb3.proxy.impl.handler.session.SessionProxyInvocationHandlerBase.invoke(SessionProxyInvocationHandlerBase.java:207)
        at org.jboss.ejb3.proxy.impl.handler.session.SessionProxyInvocationHandlerBase.invoke(SessionProxyInvocationHandlerBase.java:164)
        at $Proxy1890.register(Unknown Source)
        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.jboss.seam.util.Reflections.invoke(Reflections.java:22)
        at org.jboss.seam.intercept.RootInvocationContext.proceed(RootInvocationContext.java:32)
        at org.jboss.seam.intercept.ClientSideInterceptor$1.proceed(ClientSideInterceptor.java:76)
        at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:56)
        at org.jboss.seam.ejb.RemoveInterceptor.aroundInvoke(RemoveInterceptor.java:43)
        at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
        at org.jboss.seam.core.SynchronizationInterceptor.aroundInvoke(SynchronizationInterceptor.java:32)
        at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
        at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107)
        at org.jboss.seam.intercept.ClientSideInterceptor.invoke(ClientSideInterceptor.java:54)
        at org.javassist.tmp.java.lang.Object_$$_javassist_seam_5.register(Object_$$_javassist_seam_5.java)
        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.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:335)
        at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:348)
        at org.jboss.el.parser.AstPropertySuffix.invoke(AstPropertySuffix.java:58)
        at org.jboss.el.parser.AstValue.invoke(AstValue.java:96)
        at org.jboss.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276)
        at com.sun.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:68)
        at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
        ... 53 more
Caused by: java.lang.IllegalArgumentException: attempt to create create event with null entity
        at org.hibernate.event.PersistEvent.<init>(PersistEvent.java:45)
        at org.hibernate.event.PersistEvent.<init>(PersistEvent.java:38)
        at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:619)
        at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:623)
        at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:220)
        at org.jboss.jpa.tx.TransactionScopedEntityManager.persist(TransactionScopedEntityManager.java:187)
        at org.jboss.seam.persistence.EntityManagerProxy.persist(EntityManagerProxy.java:137)
        at org.domain.fabbiancontacts.session.RegisterAction.register(RegisterAction.java:115)
        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.jboss.aop.joinpoint.MethodInvocation.invokeTarget(MethodInvocation.java:122)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:111)
        at org.jboss.ejb3.EJBContainerInvocationWrapper.invokeNext(EJBContainerInvocationWrapper.java:69)
        at org.jboss.ejb3.interceptors.aop.InvocationContextInterceptor$InvocationContext.proceed(InvocationContextInterceptor.java:138)
        at org.jboss.seam.intercept.EJBInvocationContext.proceed(EJBInvocationContext.java:44)
        at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:56)
        at org.jboss.seam.transaction.RollbackInterceptor.aroundInvoke(RollbackInterceptor.java:28)
        at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
        at org.jboss.seam.core.BijectionInterceptor.aroundInvoke(BijectionInterceptor.java:77)
        at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
        at org.jboss.seam.core.MethodContextInterceptor.aroundInvoke(MethodContextInterceptor.java:44)
        at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
        at org.jboss.seam.persistence.EntityManagerProxyInterceptor.aroundInvoke(EntityManagerProxyInterceptor.java:29)
        at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
        at org.jboss.seam.persistence.HibernateSessionProxyInterceptor.aroundInvoke(HibernateSessionProxyInterceptor.java:30)
        at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
        at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107)
        at org.jboss.seam.intercept.SessionBeanInterceptor.aroundInvoke(SessionBeanInterceptor.java:50)
        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.jboss.ejb3.interceptors.aop.EJB3InterceptorInterceptor.invoke(EJB3InterceptorInterceptor.java:83)
        at org.jboss.ejb3.interceptors.aop.EJB3InterceptorInterceptor.invoke(EJB3InterceptorInterceptor.java:70)
        at org.jboss.ejb3.EJBContainerInvocationWrapper.invokeNext(EJBContainerInvocationWrapper.java:59)
        at org.jboss.ejb3.interceptors.aop.InterceptorSequencer.invoke(InterceptorSequencer.java:73)
        at org.jboss.ejb3.interceptors.aop.InterceptorSequencer.aroundInvoke(InterceptorSequencer.java:59)
        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.jboss.aop.advice.PerJoinpointAdvice.invoke(PerJoinpointAdvice.java:174)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.interceptors.aop.InvocationContextInterceptor.fillMethod(InvocationContextInterceptor.java:72)
        at org.jboss.aop.advice.org.jboss.ejb3.interceptors.aop.InvocationContextInterceptor_z_fillMethod_32122282.invoke(InvocationContextInterceptor_z_fillMethod_32122282.java)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.interceptors.aop.InvocationContextInterceptor.setup(InvocationContextInterceptor.java:88)
        at org.jboss.aop.advice.org.jboss.ejb3.interceptors.aop.InvocationContextInterceptor_z_setup_32122282.invoke(InvocationContextInterceptor_z_setup_32122282.java)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.connectionmanager.CachedConnectionInterceptor.invoke(CachedConnectionInterceptor.java:62)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.entity.ExtendedPersistenceContextPropagationInterceptor.invoke(ExtendedPersistenceContextPropagationInterceptor.java:60)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.entity.TransactionScopedEntityManagerInterceptor.invoke(TransactionScopedEntityManagerInterceptor.java:56)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:47)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.tx.NullInterceptor.invoke(NullInterceptor.java:42)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.ejb3.stateful.StatefulInstanceInterceptor.invoke(StatefulInstanceInterceptor.java:81)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.aspects.tx.TxPolicy.invokeInCallerTx(TxPolicy.java:126)
        ... 100 more

This is my simple User.java class:

@Entity
@Name("User")
@Scope(ScopeType.CONVERSATION)
public class User implements Serializable {

    private static final long serialVersionUID = 1L;
    private Long id;
    private String username;
    private String password;

     public User(String username, String password) {
        super();
        this.username = username;
        this.password = password;

   }

    @Id @GeneratedValue
    public Long getId() {
        return id;
    }

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

      public void setUsername(String username) {
         this.username = username;
     }
  
    @UserPrincipal
    @NotNull
    @Length(min=5,max=20,message="Username legth must be beetween 5 and 15 characters")
    public String getUsername() {
        return username;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @NotNull
    @UserPassword(hash = "SHA")
    @Length(min=5,max=15,message="Password legth must be beetween 5 and 15 characters")
    public String getPassword() {
        return password;
    }

}

This is my RegisterAction.java class:

@Stateful
@Name("Register")
@Scope(SESSION)
public class RegisterAction implements Register{
  
    @PersistenceContext
    private EntityManager entityManager;
  
    @In(required=false)
    private User user;

    public String register() {

          entityManager.persist(user);
                return "/registered.xhtml";

     }

}

This is newUser.xhtml file (only the form):

<h:form id="registration">
      <s:validateAll>
            <table>
               <tr>
                  <td>
                     <p>Username:</p>
                        </td>
                        <td>                               
                            <h:inputText value="#{User.username}" required="true"/>                               
                        </td>
                 </tr>
                 <tr>
                        <td>
                            <p>Password:</p>
                        </td>
                        <td>                               
                            <h:inputSecret value="#{User.password}" required="true"/>                         
                        </td>
                  </tr>
                   <tr>
                        <td id="tdButton">
                             <h:commandButton value="Register" action="#{Register.register}" id="button"/>
                         </td>
                   </tr>
               </table>
          </s:validateAll>
     </h:form>

Thanks for the help!


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