java.lang.NullPointerException: javax.faces.FacesException: #{loginBean.authenticate}: java.lang.NullPointerException

[panipsilos]

Hi guys , in an application I m using JPA + hibernate. However when I m trying to access the db I m getting the following error :

java.lang.NullPointerException: javax.faces.FacesException: #{loginBean.authenticate}: java.lang.NullPointerException

the exception occurs when i execute the line: EntityManager em = emf.createEntityManager();

Below you see the full serverlog.

18:21:48,174 INFO  [org.hibernate.engine.transaction.internal.TransactionFactoryInitiator] (http--0.0.0.0-8080-1) HHH000268: Transaction strategy: org.hibernate.engine.transaction.internal.jta.CMTTransactionFactory

18:21:48,177 INFO  [org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory] (http--0.0.0.0-8080-1) HHH000397: Using ASTQueryTranslatorFactory

18:21:48,189 INFO  [org.hibernate.tool.hbm2ddl.SchemaUpdate] (http--0.0.0.0-8080-1) HHH000228: Running hbm2ddl schema update

18:21:48,191 INFO  [org.hibernate.tool.hbm2ddl.SchemaUpdate] (http--0.0.0.0-8080-1) HHH000102: Fetching database metadata

18:21:48,193 INFO  [org.hibernate.tool.hbm2ddl.SchemaUpdate] (http--0.0.0.0-8080-1) HHH000396: Updating schema

18:21:48,195 INFO  [org.hibernate.tool.hbm2ddl.SchemaUpdate] (http--0.0.0.0-8080-1) HHH000232: Schema update complete

18:22:08,153 WARNING [javax.enterprise.resource.webcontainer.jsf.lifecycle] (http--0.0.0.0-8080-1) #{loginBean.authenticate}: java.lang.NullPointerException: javax.faces.FacesException: #{loginBean.authenticate}: java.lang.NullPointerException

    at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:118) [jsf-impl-2.1.7-jbossorg-2.jar:]

    at javax.faces.component.UICommand.broadcast(UICommand.java:315) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]

    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]

    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]

    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81) [jsf-impl-2.1.7-jbossorg-2.jar:]

    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) [jsf-impl-2.1.7-jbossorg-2.jar:]

    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) [jsf-impl-2.1.7-jbossorg-2.jar:]

    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:329) [jbossweb-7.0.13.Final.jar:]

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]

    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275) [jbossweb-7.0.13.Final.jar:]

    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161) [jbossweb-7.0.13.Final.jar:]

    at org.jboss.as.jpa.interceptor.WebNonTxEmCloserValve.invoke(WebNonTxEmCloserValve.java:50) [jboss-as-jpa-7.1.1.Final.jar:7.1.1.Final]

    at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:153) [jboss-as-web-7.1.1.Final.jar:7.1.1.Final]

    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:155) [jbossweb-7.0.13.Final.jar:]

    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [jbossweb-7.0.13.Final.jar:]

    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) [jbossweb-7.0.13.Final.jar:]

    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:368) [jbossweb-7.0.13.Final.jar:]

    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877) [jbossweb-7.0.13.Final.jar:]

    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:671) [jbossweb-7.0.13.Final.jar:]

    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:930) [jbossweb-7.0.13.Final.jar:]

    at java.lang.Thread.run(Unknown Source) [rt.jar:1.6.0_32]

Caused by: javax.faces.el.EvaluationException: java.lang.NullPointerException

    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:102) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]

    at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) [jsf-impl-2.1.7-jbossorg-2.jar:]

    ... 21 more

Caused by: java.lang.NullPointerException

    at org.hibernate.engine.transaction.internal.jta.JtaStatusHelper.getStatus(JtaStatusHelper.java:73) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]

    at org.hibernate.engine.transaction.internal.jta.JtaStatusHelper.isActive(JtaStatusHelper.java:115) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]

    at org.hibernate.engine.transaction.internal.jta.CMTTransaction.join(CMTTransaction.java:149) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]

    at org.hibernate.ejb.AbstractEntityManagerImpl.joinTransaction(AbstractEntityManagerImpl.java:1207) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]

    at org.hibernate.ejb.AbstractEntityManagerImpl.postInit(AbstractEntityManagerImpl.java:176) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]

    at org.hibernate.ejb.EntityManagerImpl.<init>(EntityManagerImpl.java:89) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]

    at org.hibernate.ejb.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:125) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]

    at org.hibernate.ejb.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:120) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]

    at org.Handlers.UserHandler.getAllUsers(UserHandler.java:32) [classes:]

    at org.tutorial.LoginBean.authenticate(LoginBean.java:50) [classes:]

    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.6.0_32]

    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) [rt.jar:1.6.0_32]

    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) [rt.jar:1.6.0_32]

    at java.lang.reflect.Method.invoke(Unknown Source) [rt.jar:1.6.0_32]

    at org.apache.el.parser.AstValue.invoke(AstValue.java:262) [jbossweb-7.0.13.Final.jar:]

    at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:278) [jbossweb-7.0.13.Final.jar:]

    at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105) [jsf-impl-2.1.7-jbossorg-2.jar:]

    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]

    ... 22 more

My guess is that, for some reason ,  it has to do with the entity manager. I m really new to using hibernate and JPA . I also attach a class to shwo you how I access the db. Could someone figure out what I m doing wrong?

public class ProjectHandler {

    public void create(Project project)

    {

        EntityManagerFactory emf = Persistence.createEntityManagerFactory("ResearchManagement.Data");

        EntityManager em = emf.createEntityManager();

        em.getTransaction().begin();

        em.persist(project);

        em.getTransaction().commit();

        em.close();

    }

    public List<Project> getAllProjects()

    {

        EntityManagerFactory emf = Persistence.createEntityManagerFactory("ResearchManagement.Data");

        EntityManager em = emf.createEntityManager();

        em.getTransaction().begin();

        Query query = em.createQuery("SELECT p FROM Project p");

        List<Project> projects = query.getResultList();

        em.getTransaction().commit();

        em.close();

        return projects;

    }

    public int deleteByProjectName(String projectName)

    {

        EntityManagerFactory emf = Persistence.createEntityManagerFactory("ResearchManagement.Data");

        EntityManager em = emf.createEntityManager();

        em.getTransaction().begin();

        Query q = em.createQuery("DELETE FROM Project p WHERE p.projectName = :u");

        q.setParameter("u", projectName );

        int deleted = q.executeUpdate();

        em.getTransaction().commit();

        em.close();

        return deleted;

    }

[nickarls]

What happens in at org.Handlers.UserHandler.getAllUsers(UserHandler.java:32) ?

[panipsilos]

public class UserHandler {

    public void create(User user)

    {

        EntityManagerFactory emf = Persistence.createEntityManagerFactory("ResearchManagement.Data");

        EntityManager em = emf.createEntityManager();

        em.getTransaction().begin();

        em.persist(user);

        em.getTransaction().commit();

        em.close();

    }

    public List<User> getAllUsers()

    {

        EntityManagerFactory emf = Persistence.createEntityManagerFactory("ResearchManagement.Data");

Line 32 --->       EntityManager em = emf.createEntityManager();

        em.getTransaction().begin();

        Query query = em.createQuery("SELECT p FROM User p");

        List<User> users = query.getResultList();

        em.getTransaction().commit();

        em.close();

        return users;

    }

    public int deleteByUsername(String userName)

    {

        EntityManagerFactory emf = Persistence.createEntityManagerFactory("ResearchManagement.Data");

        EntityManager em = emf.createEntityManager();

        em.getTransaction().begin();

        Query q = em.createQuery("DELETE FROM User u WHERE u.userName = :u");

        q.setParameter("u", userName );

        int deleted = q.executeUpdate();

        em.getTransaction().commit();

        em.close();

        return deleted;

    }

}

At line 32 I create the entity manager. So again my guess that the entity manager is null, but I cant get why.

[nickarls]

It could also be that emf is null (is the name of the PU correct)?

More to the point, what is the running environment? Why aren't you using @PersistenceContext injection for your EntityManager?

[nickarls]

something like

@Stateful
@Model
public class UserBean {
 @PersistenceContext
  private EntityManager em;

  public void save() {
    em.persist(something);
  }

}

would appear to do the job without the pesky stuff of managing transactions and getting entitymanagers....

[panipsilos]

Well I m using JPA and Hibernate for data layer and JSF for UI. i m running it on a JBoss. I auto-generated all the entities using the JPA project from Eclipse. So i didnt really concern with using annotations.

Thing is that I m pretty new to all these frameowrks and I m missing basic knowledge.  Could you please recommend me a good tutorial/handbook for getting an insight on these things?

Concerning the PU, the name is correct since I had it workign before switiching to using a datasource.

Initally I had the configuration of the connection to the database in the persistence.xml , without using any -ds.xml or the standalone.xml

<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="ResearchManagement.Data">

        <class>org.Entities.Department</class>

        <class>org.Entities.Employee</class>

        <class>org.Entities.Partner</class>

        <class>org.Entities.Project</class>

        <class>org.Entities.User</class>

    <properties>

    <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>

    <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>     

    <property name="hibernate.connection.url" value="jdbc:mysql://127.0.0.1:3306/researchprojects"/>

    <property name="hibernate.connection.username" value="root"/>

    <property name="hibernate.connection.password" value="root"/>

    <property name="hibernate.hbm2ddl.auto" value="update"/>

    </properties>

    </persistence-unit>

</persistence>

[nickarls]

(Besides, creating an EMF for each operation is very expensive)

I think you'll find various tutorials from http://www.jboss.org/developer

[panipsilos]

thnx , once again you were very helpful to me.

[panipsilos]

Well actually the problem still remains. I debug the application and I see that the emf is not null. However it seems to return a null entity manager.

What I noticed and looks strange  the server log when I run the application.  it reads the pesistence unit and connects to the db reading corerclty all the tables:

12:02:06,094 INFO  [org.hibernate.validator.util.Version] (MSC service thread 1-3) Hibernate Validator 4.2.0.Final

12:02:06,328 INFO  [org.hibernate.tool.hbm2ddl.SchemaUpdate] (MSC service thread 1-3) HHH000228: Running hbm2ddl schema update

12:02:06,328 INFO  [org.hibernate.tool.hbm2ddl.SchemaUpdate] (MSC service thread 1-3) HHH000102: Fetching database metadata

12:02:06,328 INFO  [org.hibernate.tool.hbm2ddl.SchemaUpdate] (MSC service thread 1-3) HHH000396: Updating schema

12:02:06,343 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000261: Table found: researchprojects.departments

12:02:06,343 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000037: Columns: [phonenumber, departmentid, name, city]

12:02:06,343 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000108: Foreign keys: []

12:02:06,343 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000126: Indexes: [primary]

12:02:06,359 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000261: Table found: researchprojects.employees

12:02:06,359 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000037: Columns: [phonenumber, departmentid, employeeid, lastname, firstname]

12:02:06,359 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000108: Foreign keys: [fk9d39ef85d77ba982]

12:02:06,359 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000126: Indexes: [fk9d39ef85d77ba982, primary]

12:02:06,374 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000261: Table found: researchprojects.partners

12:02:06,374 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000037: Columns: [partnerid, name, contactmail, city]

12:02:06,374 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000108: Foreign keys: []

12:02:06,374 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000126: Indexes: [primary]

12:02:06,374 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000261: Table found: researchprojects.projects

12:02:06,390 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000037: Columns: [departmentid, duration, description, projectname, projectid]

12:02:06,390 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000108: Foreign keys: [fkc479187ad77ba982]

12:02:06,390 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000126: Indexes: [primary, fkc479187ad77ba982]

12:02:06,390 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000261: Table found: researchprojects.projects_has_employees

12:02:06,390 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000037: Columns: [projects_projectid, employees_employeeid]

12:02:06,390 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000108: Foreign keys: [fk294f111bcd3ec025, fk294f111b92772ef4]

12:02:06,390 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000126: Indexes: [fk294f111bcd3ec025, primary, fk294f111b92772ef4]

12:02:06,406 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000261: Table found: researchprojects.projects_has_partners

12:02:06,406 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000037: Columns: [partners_partnerid, projects_projectid]

12:02:06,406 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000108: Foreign keys: [fk8d741055cd3ec025, fk8d7410555290eb4]

12:02:06,406 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000126: Indexes: [fk8d741055cd3ec025, fk8d7410555290eb4, primary]

12:02:06,421 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000261: Table found: researchprojects.users

12:02:06,421 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000037: Columns: [username, userid, password]

12:02:06,421 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000108: Foreign keys: []

12:02:06,421 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000126: Indexes: [primary]

12:02:06,421 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000261: Table found: researchprojects.hibernate_sequence

12:02:06,437 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000037: Columns: [next_val]

12:02:06,437 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000108: Foreign keys: []

12:02:06,437 INFO  [org.hibernate.tool.hbm2ddl.TableMetadata] (MSC service thread 1-3) HHH000126: Indexes: []

12:02:06,437 INFO  [org.hibernate.tool.hbm2ddl.SchemaUpdate] (MSC service thread 1-3) HHH000232: Schema update complete

However when I m trying to read the user table (getallUsers() ) , it creates the emf and at the log i see:

12:03:53,346 INFO  [org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory] (http--0.0.0.0-8080-1) HHH000397: Using ASTQueryTranslatorFactory

12:03:53,347 INFO  [org.hibernate.tool.hbm2ddl.SchemaUpdate] (http--0.0.0.0-8080-1) HHH000228: Running hbm2ddl schema update

12:03:53,347 INFO  [org.hibernate.tool.hbm2ddl.SchemaUpdate] (http--0.0.0.0-8080-1) HHH000102: Fetching database metadata

12:03:53,347 INFO  [org.hibernate.tool.hbm2ddl.SchemaUpdate] (http--0.0.0.0-8080-1) HHH000396: Updating schema

12:03:53,347 INFO  [org.hibernate.tool.hbm2ddl.SchemaUpdate] (http--0.0.0.0-8080-1) HHH000232: Schema update complete

That means that it cannot read the tables anymore. Does this mean anything to you ?

[nickarls]

A non-null EMF returning a null EM without an exception being thrown sounds a bit strange.

I'm not sure what side-effects running multiple EMF boostrapping calls with name="hibernate.hbm2ddl.auto" value="update"/> could do but apparently the tables themselves survive.

[panipsilos]

Ok I ll investigate further into it. Thnk you for your help