@Stateless NullPointerException

Question

Я новичок с EJB3.

Я создал пользователя dao.

@Entity 
@Table(name = "t_user") 
public class User implements Serializable { 

    @Column(name = "name") 
    private String name; 

    private String street; 
    private int houseNumber; 

    @Column(name = "email") 
    private String email; 
//... getters and setters 

} 

без гражданства EJB:

@Stateless 
public class ItemFacade implements Serializable { 

    /** 
    * 
    */ 
    private static final long serialVersionUID = 1L; 
    @PersistenceContext(unitName = "databaseName") 
    private EntityManager em; 

    public void create(User user) { 
     em.persist(user); 
    } 
} 

Управляемая боб:

@ManagedBean 
@ViewScoped 
public class UserBean implements Serializable { 
    private User user = new User(); 
    @EJB 
    private ItemFacade itemFacade; 
    public void save(){  
     itemFacade.create(this.user); 
    } 
    //.... 
} 

persistence.xml

<?xml version="1.0" encoding="UTF-8"?> 
<persistence version="2.0" 
    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_2_0.xsd"> 
     <persistence-unit name="my-unit" > 
      <jta-data-source>TestDS</jta-data-source> 
     </persistence-unit> 
</persistence> 

И tomee.xml

<?xml version="1.0" encoding="UTF-8"?> 
<tomee> 
    <!-- see http://tomee.apache.org/containers-and-resources.html --> 

    <!-- activate next line to be able to deploy applications in apps --> 
    <!-- <Deployments dir="apps" /> --> 
    <Resource id="TestDS" type="DataSource"> 
     JdbcDriver com.mysql.jdbc.Driver 
     JdbcUrl jdbc:mysql://localhost:3306/databaseName 
     UserName username 
     Password password 
     JtaManaged true 
    </Resource> 
</tomee> 

Но я получаю NullPointerException, когда я пытаюсь сохранить пользователя в строке:

itemFacade.create(this.user); 

Любая помощь будет оценена.

Полный StackTrace является:

ADVERTENCIA: java.lang.NullPointerException 
javax.el.ELException: java.lang.NullPointerException 
    at org.apache.el.parser.AstValue.invoke(AstValue.java:291) 
    at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:273) 
    at javax.faces.event.MethodExpressionActionListener.processAction(MethodExpressionActionListener.java:149) 
    at javax.faces.event.ActionEvent.processListener(ActionEvent.java:88) 
    at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:813) 
    at javax.faces.component.UICommand.broadcast(UICommand.java:300) 
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790) 
    at javax.faces.component.UIViewRoot.processDecodes(UIViewRoot.java:931) 
    at com.sun.faces.lifecycle.ApplyRequestValuesPhase.execute(ApplyRequestValuesPhase.java:78) 
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) 
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198) 
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:646) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) 
    at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:105) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) 
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) 
    at org.apache.tomee.catalina.OpenEJBValve.invoke(OpenEJBValve.java:44) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) 
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) 
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070) 
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611) 
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) 
    at java.lang.Thread.run(Thread.java:745) 
Caused by: java.lang.NullPointerException 
    at managedBeans.UserBean.create(UserBean.java:11) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
    at java.lang.reflect.Method.invoke(Method.java:606) 
    at org.apache.el.parser.AstValue.invoke(AstValue.java:278) 
    ... 34 more 

Как я могу создать EntityManager не пустой?

Answer 1

Спасибо вам, это UnitName имя базы данных ? Я ставлю в обоих местах то же самое имя, но я по-прежнему с NullPointe

я решить ее:

public void save(){ 
     itemFacade = new ItemFacade(); 
     itemFacade.create(this.user); 
} 

Answer 2

Похоже, что ваш менеджер объектов не вводится.

Изменить @PersistenceContext(unitName = "databaseName")

в

@PersistenceContext(unitName = "my-unit")

Как это должно соответствовать тому, что у вас есть в вашем persistance.xml <persistence-unit name="my-unit" >