Configurar postgre e jpa

Olá pessoa
estou com dificuldades para se conectar com o postgre
atraves da JPA,
Realizei um teste com o banco que vem junto com o java
e com o netbeans ele se comportou normalmente
so que quando eu fui testar no postgre ele não consegue se
conectar e esta dando erro de ponteiro nulo
estou usando as tecnologias EJB 3.0, JPA e JSF queria saber
sem tem alguma configuração
aqui vai o erro

naming.bind **RemoteBusinessJndiName: br.gdcom.web.ejbs.ProfessorRemote; remoteBusIntf: br.gdcom.web.ejbs.ProfessorRemote LDR5010: All ejb(s) of [ProfOnLine] loaded successfully! WEB0100: Loading web module [ProfOnLine:ProfessorOnLine.war] in virtual server [server] at [/ProfessorOnLine] naming.bind Initializing Sun's JavaServer Faces implementation (1.2_02-b03-FCS) for context '/ProfessorOnLine' Completed initializing Sun's JavaServer Faces implementation (1.2_02-b03-FCS) for context '/ProfessorOnLine' [TopLink Config]: 2007.05.29 04:48:57.915--ServerSession(20348011)--property toplink.server.platform.class.name is deprecated, property toplink.target-server should be used instead. topLink_version application_server_name_and_version platform=>PostgreSQLPlatform user name=> "" connector=>JNDIConnector datasource name=>null );|connecting ;|connected_user_database_driver platform=>PostgreSQLPlatform user name=> "" connector=>JNDIConnector datasource name=>null );|connecting ;|connected_user_database_driver disconnect logout_successful EJB5018: An exception was thrown during an ejb invocation on [ProfessorBean] javax.ejb.EJBException at com.sun.ejb.containers.BaseContainer.processSystemException(BaseContainer.java:3730) at com.sun.ejb.containers.BaseContainer.completeNewTx(BaseContainer.java:3630) at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:3431) at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:1247) at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:192) at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:71) at $Proxy61.professor(Unknown Source) at br.gdcom.web.admin.login.btnLogin_action(login.java:355) 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.sun.el.parser.AstValue.invoke(AstValue.java:151) at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:283) at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:77) at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:96) at com.sun.rave.web.ui.appbase.faces.ActionListenerImpl.processAction(ActionListenerImpl.java:57) at javax.faces.component.UICommand.broadcast(UICommand.java:383) at com.sun.webui.jsf.component.WebuiCommand.broadcast(WebuiCommand.java:145) at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:450) at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:759) at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:97) at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:244) at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:113) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:244) at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:397) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:184) at com.sun.webui.jsf.util.UploadFilter.doFilter(UploadFilter.java:203) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:216) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:184) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:276) at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:536) at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:240) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:179) at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566) at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:73) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:182) at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566) at com.sun.enterprise.web.VirtualServerPipeline.invoke(VirtualServerPipeline.java:120) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:939) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:137) at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:536) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:939) at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:239) at com.sun.enterprise.web.connector.grizzly.ProcessorTask.invokeAdapter(ProcessorTask.java:667) at com.sun.enterprise.web.connector.grizzly.ProcessorTask.processNonBlocked(ProcessorTask.java:574) at com.sun.enterprise.web.connector.grizzly.ProcessorTask.process(ProcessorTask.java:844) at com.sun.enterprise.web.connector.grizzly.ReadTask.executeProcessorTask(ReadTask.java:287) at com.sun.enterprise.web.connector.grizzly.ReadTask.doTask(ReadTask.java:212) at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:252) at com.sun.enterprise.web.connector.grizzly.WorkerThread.run(WorkerThread.java:75) Caused by: java.lang.NullPointerException at oracle.toplink.essentials.platform.database.PostgreSQLPlatform.platformSpecificSequencingInitialization(PostgreSQLPlatform.java:413) at oracle.toplink.essentials.internal.sequencing.SequencingManager.onConnect(SequencingManager.java:568) at oracle.toplink.essentials.internal.sessions.DatabaseSessionImpl.initializeSequencing(DatabaseSessionImpl.java:137) at oracle.toplink.essentials.internal.sessions.DatabaseSessionImpl.initializeDescriptors(DatabaseSessionImpl.java:371) at oracle.toplink.essentials.internal.sessions.DatabaseSessionImpl.initializeDescriptors(DatabaseSessionImpl.java:360) at oracle.toplink.essentials.internal.sessions.DatabaseSessionImpl.postConnectDatasource(DatabaseSessionImpl.java:677) at oracle.toplink.essentials.internal.sessions.DatabaseSessionImpl.loginAndDetectDatasource(DatabaseSessionImpl.java:559) at oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:180) at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:230) at oracle.toplink.essentials.internal.ejb.cmp3.base.EntityManagerFactoryImpl.getServerSession(EntityManagerFactoryImpl.java:78) at oracle.toplink.essentials.internal.ejb.cmp3.base.EntityManagerFactoryImpl.createEntityManagerImpl(EntityManagerFactoryImpl.java:113) at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:84) at com.sun.enterprise.util.EntityManagerWrapper._getDelegate(EntityManagerWrapper.java:166) at com.sun.enterprise.util.EntityManagerWrapper.find(EntityManagerWrapper.java:239) at br.gdcom.web.ejbs.ProfessorBean.professor(ProfessorBean.java:36) 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.sun.enterprise.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1050) at com.sun.enterprise.security.SecurityUtil.invoke(SecurityUtil.java:165) at com.sun.ejb.containers.BaseContainer.invokeTargetBeanMethod(BaseContainer.java:2766) at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:3847) at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:184) ... 49 more java.lang.NullPointerException javax.faces.el.EvaluationException: java.lang.NullPointerException

Quem puder me ajudar eu agradeço!!!

Verifique seu arquivo persistence.xml de configuração:

<?xml version="1.0" encoding="UTF-8"?>
<!-- example of a default persistence.xml -->
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
             version="1.0">
    <persistence-unit name="jpa_hibernate">
        <properties>
            <property name="hibernate.hbm2ddl.auto" value="none"/>
            <property name="hibernate.format_sql" value="true"/>
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect"/>
            <property name="hibernate.connection.driver_class" value="org.postgresql.Driver"/>
            <property name="hibernate.connection.username" value="username"/>
            <property name="hibernate.connection.password" value="password"/>
            <property name="hibernate.connection.url" value="jdbc:postgresql://localhost:5432/nome_base"/>
        </properties>
    </persistence-unit>
</persistence>

Você esta usando com Toplink?, todos os jars foram adicionados corretamente?

De uma olhada aqui:

http://blog.caelum.com.br/video/jpa/beginning-with-jpa.html

Olá
estou usando o toplink
eo netbeans so que quando crio o persistence.xml
ele cria um poll de conexoes queria saber se esse
poll de conexoes é obrigatório para aplicações J2EE
e queria saber tambem se naum é alguma configuração
do postgre que pode esta me impedindo de se conectar?

Desde ja Obrigado!!!