Java Development Tools

Hi,

i m using oracle 10g Express, JDev 11g ; Tuto : http://st-curriculum.oracle.com/obe/jdev/obe11jdev/ps1/ejb/ejb.html

i have that error and i don't understand the reason of it,

Exception [EclipseLink-7060] (Eclipse Persistence Services - 2.0.2.v20100323-r6872): org.eclipse.persistence.exceptions.ValidationException
Exception Description: Cannot acquire data source [java:/app/jdbc/jdbc/HRConnDS].
Internal Exception: javax.naming.NameNotFoundException: While trying to look up /app/jdbc/jdbc/HRConnDS in /app/ejb/EJBModelEJB.jar#HRFacade.; remaining name '/app/jdbc/jdbc/HRConnDS'
at org.eclipse.persistence.exceptions.ValidationException.cannotAcquireDataSource(ValidationException.java:451)
at org.eclipse.persistence.sessions.JNDIConnector.connect(JNDIConnector.java:116)
at org.eclipse.persistence.sessions.JNDIConnector.connect(JNDIConnector.java:94)
at org.eclipse.persistence.sessions.DatasourceLogin.connectToDatasource(DatasourceLogin.java:162)
at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.loginAndDetectDatasource(DatabaseSessionImpl.java:584)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:228)
at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:369)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.getServerSession(EntityManagerFactoryImpl.java:151)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManagerImpl(EntityManagerFactoryImpl.java:207)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:195)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at weblogic.deployment.EntityManagerFactoryProxyImpl.invoke(EntityManagerFactoryProxyImpl.java:87)
at $Proxy128.createEntityManager(Unknown Source)
at weblogic.deployment.TransactionalEntityManagerProxyImpl.newPersistenceContext(TransactionalEntityManagerProxyImpl.java:75)
at weblogic.deployment.BasePersistenceContextProxyImpl.getPersistenceContext(BasePersistenceContextProxyImpl.java:160)
at weblogic.deployment.BasePersistenceContextProxyImpl.invoke(BasePersistenceContextProxyImpl.java:88)
at weblogic.deployment.TransactionalEntityManagerProxyImpl.invoke(TransactionalEntityManagerProxyImpl.java:91)
at weblogic.deployment.BasePersistenceContextProxyImpl.invoke(BasePersistenceContextProxyImpl.java:80)
at weblogic.deployment.TransactionalEntityManagerProxyImpl.invoke(TransactionalEntityManagerProxyImpl.java:26)
at $Proxy130.createNamedQuery(Unknown Source)
at oracle.HRFacadeBean.getEmployeesFindAll(HRFacadeBean.java:46)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.bea.core.repackaged.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:310)
at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
at com.bea.core.repackaged.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:131)
at com.bea.core.repackaged.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:119)
at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
at com.bea.core.repackaged.springframework.jee.spi.MethodInvocationVisitorImpl.visit(MethodInvocationVisitorImpl.java:37)
at weblogic.ejb.container.injection.EnvironmentInterceptorCallbackImpl.callback(EnvironmentInterceptorCallbackImpl.java:54)
at com.bea.core.repackaged.springframework.jee.spi.EnvironmentInterceptor.invoke(EnvironmentInterceptor.java:50)
at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
at com.bea.core.repackaged.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)
at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
at com.bea.core.repackaged.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:131)
at com.bea.core.repackaged.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:119)
at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
at com.bea.core.repackaged.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
at $Proxy132.getEmployeesFindAll(Unknown Source)
at oracle.HRFacade_mg5i94_HRFacadeImpl.getEmployeesFindAll(HRFacade_mg5i94_HRFacadeImpl.java:447)
at oracle.HRFacade_mg5i94_HRFacadeImpl_WLSkel.invoke(Unknown Source)
at weblogic.rmi.internal.BasicServerRef.invoke(BasicServerRef.java:589)
at weblogic.rmi.cluster.ClusterableServerRef.invoke(ClusterableServerRef.java:230)
at weblogic.rmi.internal.BasicServerRef$1.run(BasicServerRef.java:477)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:363)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:147)
at weblogic.rmi.internal.BasicServerRef.handleRequest(BasicServerRef.java:473)
at weblogic.rmi.internal.wls.WLSExecuteRequest.run(WLSExecuteRequest.java:118)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)
Caused by: javax.naming.NameNotFoundException: While trying to look up /app/jdbc/jdbc/HRConnDS in /app/ejb/EJBModelEJB.jar#HRFacade.; remaining name '/app/jdbc/jdbc/HRConnDS'
at weblogic.jndi.internal.BasicNamingNode.newNameNotFoundException(BasicNamingNode.java:1139)
at weblogic.jndi.internal.ApplicationNamingNode.lookup(ApplicationNamingNode.java:144)
at weblogic.jndi.internal.WLEventContextImpl.lookup(WLEventContextImpl.java:254)
at weblogic.jndi.internal.WLContextImpl.lookup(WLContextImpl.java:393)
at weblogic.jndi.factories.java.ReadOnlyContextWrapper.lookup(ReadOnlyContextWrapper.java:45)
at weblogic.jndi.internal.AbstractURLContext.lookup(AbstractURLContext.java:135)
at javax.naming.InitialContext.lookup(InitialContext.java:396)
at org.eclipse.persistence.sessions.JNDIConnector.connect(JNDIConnector.java:110)
... 54 more
>



the *-jdbc.xml file was created in META-INF folder...

I need help please... Any ideas??