Problems with @Stateless and application startup on JBoss 6

问题

I have created a Java Web project with just one class. If I compile and deploy the WAR to JBoss everything works fine. However, if I make the class @Stateless, JBoss deployment fails with the error.

java.lang.IllegalArgumentException: EntityManagerFactory cannot be null

I am (by now) sure that I must be doing something very stupid but I cannot see what my problem is.

Update: Must be something with the installation I have been given. Works fine on a local install of JBoss 6.

Larger stacke trace quote:

2012-01-28 01:43:54,913 INFO  [org.jboss.ejb3.deployers.JBossASKernel] (HDScanner) installing bean: jboss.j2ee:jar=JanTest.war,name=Service,service=EJB3
2012-01-28 01:43:54,914 INFO  [org.jboss.ejb3.deployers.JBossASKernel] (HDScanner)   with dependencies:
2012-01-28 01:43:54,914 INFO  [org.jboss.ejb3.deployers.JBossASKernel] (HDScanner)   and demands:
2012-01-28 01:43:54,914 INFO  [org.jboss.ejb3.deployers.JBossASKernel] (HDScanner)  jboss-injector:topLevelUnit=JanTest.war,unit=JanTest.war,bean=Service,interceptor=org.jboss.weld.integration.ejb.SessionBeanInterceptor; Required: Described
2012-01-28 01:43:54,914 INFO  [org.jboss.ejb3.deployers.JBossASKernel] (HDScanner)  jboss.ejb:service=EJBTimerService; Required: Described
2012-01-28 01:43:54,914 INFO  [org.jboss.ejb3.deployers.JBossASKernel] (HDScanner)  jboss-injector:topLevelUnit=JanTest.war,unit=JanTest.war,bean=Service,interceptor=org.jboss.weld.integration.ejb.interceptor.Jsr299BindingsInterceptor; Required: Described
2012-01-28 01:43:54,914 INFO  [org.jboss.ejb3.deployers.JBossASKernel] (HDScanner)  jboss-switchboard:appName=JanTest,module=JanTest; Required: Create
2012-01-28 01:43:54,915 INFO  [org.jboss.ejb3.deployers.JBossASKernel] (HDScanner)   and supplies:
2012-01-28 01:43:54,915 INFO  [org.jboss.ejb3.deployers.JBossASKernel] (HDScanner)  jndi:Service
2012-01-28 01:43:54,915 INFO  [org.jboss.ejb3.deployers.JBossASKernel] (HDScanner) Added bean(jboss.j2ee:jar=JanTest.war,name=Service,service=EJB3) to KernelDeployment of: JanTest.war
2012-01-28 01:43:55,175 INFO  [org.jboss.web.tomcat.service.deployers.TomcatDeployment] (HDScanner) deploy, ctxPath=/JanTest
2012-01-28 01:43:55,318 ERROR [org.jboss.kernel.plugins.dependency.AbstractKernelController] (HDScanner) Error installing to Create: name=jboss.j2ee:jar=JanTest.war,name=Service,service=EJB3 state=Configured: java.lang.IllegalArgumentException: EntityManagerFactory cannot be null
    at org.jboss.ejb3.timerservice.mk2.TimerServiceImpl.<init>(TimerServiceImpl.java:139) [:1.0.0-alpha-13]
    at org.jboss.ejb3.timerservice.mk2.TimerServiceFactoryImpl.createTimerService(TimerServiceFactoryImpl.java:79) [:1.0.0-alpha-13]
    at org.jboss.ejb3.TimerServiceContainer.createTimerService(TimerServiceContainer.java:234) [:1.7 ......

回答1:

The problem occurred only in the particular installation of JBoss. Worked fine with a local install. I'll post a comment should I ever find the reason for the error.

来源：https://stackoverflow.com/questions/9042032/problems-with-stateless-and-application-startup-on-jboss-6