Struts 2 + Spring 3 +Hibernate 3.5 Integration Problem session factory nullpointer exception

[Tony Manello]

Hi I'm new using these frameworks. I've used this tutorial as a starting point. My problem is that none of my actions work. When the jsp input form is shown and you submit the values I get this error:

  
Struts Problem Report

Struts has detected an unhandled exception:
Messages: 	
File: 	Presentacion/registrado/actions/Login.java
Line number: 	19
Stacktraces
java.lang.NullPointerException

    Presentacion.registrado.actions.Login.execute(Login.java:19)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    java.lang.reflect.Method.invoke(Method.java:597)
    com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:441)
    com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:280)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:243)
    com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:165)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:252)
    org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:179)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:130)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:165)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:179)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
    org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:488)
    org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    com.opensymphony.sitemesh.webapp.SiteMeshFilter.obtainContent(SiteMeshFilter.java:129)
    com.opensymphony.sitemesh.webapp.SiteMeshFilter.doFilter(SiteMeshFilter.java:77)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
    org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
    org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
    org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
    java.lang.Thread.run(Thread.java:619)
    

You are seeing this page because development mode is enabled. Development mode, or devMode, enables extra debugging behaviors and reports to assist developers. To disable this mode, set:

  struts.devMode=false

in your WEB-INF/classes/struts.properties file.
  

My Spring application context is as follows:

  <?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="
       http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/tx
       http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
       http://www.springframework.org/schema/aop
       http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">

    <!-- The singleton hibernate session factory -->
    <bean id="sessionFactory" scope="singleton"
		class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
        <property name="configLocation" value="classpath:hibernate.cfg.xml" />
    </bean>

    <!-- Spring's hibernate transaction manager, in charge of making hibernate sessions/txns -->
    <bean id="transactionManager"
		class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>

    <!-- So classes/functions with @Transactional get a hibernate txn -->
    <tx:annotation-driven />

    <!-- Inject my business services class to the actions -->
    <bean id="logica" class="Logica.LogicaComun" scope="singleton">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>
</beans>  

My hibernate.cfg is:

  <?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
	<!-- Database connection settings -->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost:3306/PFC</property>
        <property name="connection.username">root</property>
        <property name="connection.password">root</property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

	<!--
		Enable c3p0 connection pooling, because hibernate pooling is not
		prod-ready. Apparently connection.provider_class is needed in
		hibernate 3+
	-->
        <property name="connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>
        <property name="c3p0.max_size">100</property>
        <property name="c3p0.min_size">1</property>
        <property name="c3p0.idle_test_period">30</property>

	<!-- Echo all executed SQL to stdout for debugging -->
        <property name="show_sql">true</property>

	<!-- All the entity classes for hibernate to check for annotations here
        -->
        <mapping class="ObjetosDeNegocio.CambiosRitmo" />
        <mapping class="ObjetosDeNegocio.CambiosRitmoRitmos" />
        <mapping class="ObjetosDeNegocio.CambiosRitmoRitmosPK" />
        <mapping class="ObjetosDeNegocio.Carrera" />
        <mapping class="ObjetosDeNegocio.CarreraContinua" />
        <mapping class="ObjetosDeNegocio.Corredor" />
        <mapping class="ObjetosDeNegocio.Ejercicio" />
        <mapping class="ObjetosDeNegocio.Estiramientos" />
        <mapping class="ObjetosDeNegocio.Modalidad" />
        <mapping class="ObjetosDeNegocio.Nota" />
        <mapping class="ObjetosDeNegocio.NotaPK" />
        <mapping class="ObjetosDeNegocio.Pesas" />
        <mapping class="ObjetosDeNegocio.Plan" />
        <mapping class="ObjetosDeNegocio.Progresivo" />
        <mapping class="ObjetosDeNegocio.Registrado" />
        <mapping class="ObjetosDeNegocio.Resultado" />
        <mapping class="ObjetosDeNegocio.ResultadoPK" />
        <mapping class="ObjetosDeNegocio.Ritmo" />
        <mapping class="ObjetosDeNegocio.Seguimiento" />
        <mapping class="ObjetosDeNegocio.SeguimientoPK" />
        <mapping class="ObjetosDeNegocio.Serie" />
        <mapping class="ObjetosDeNegocio.Sesion" />
        <mapping class="ObjetosDeNegocio.SesionRealizada" />
        <mapping class="ObjetosDeNegocio.SesionRealizadaPK" />
    </session-factory>
</hibernate-configuration>  

Struts.xml:

  <?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
    <constant name="struts.devMode" value="true" /> <!-- set to false for prod -->
    <package name="PresentacionRegistrado" extends="struts-default">
        <action name="*" class="Presentacion.registrado.actions.{1}">
            <result>/vistas/registrado/{1}.jsp</result>
            <result name="redirect" type="redirect">${redirectUrl}</result>
        </action>
    </package>
</struts>
  

The base action is:

  package Presentacion.registrado.actions;

import Logica.LogicaComun;
import com.opensymphony.xwork2.ActionSupport;

public class AccionBase extends ActionSupport {
    // So that spring can inject the business singleton

    protected LogicaComun logicaComun;

    public void setLogicaComun(LogicaComun value) {
        logicaComun = value;
    }

    // For redirect results
    protected String redirectUrl;

    public String getRedirectUrl() {
        return redirectUrl;
    }

    public String redirect(String to) {
        redirectUrl = to;
        return "redirect";
    }
}
 

And the Login action:

  public class Login extends AccionBase {

    @Override
    public String execute() {
        if (nombre_usuario != null && nombre_usuario.length() > 0 && contrasenia != null && contrasenia.length() > 0) {
            if (logicaComun.login(nombre_usuario, contrasenia) == true) {//if (nombre_usuario.equals("admin") && contrasenia.equals("admin")) {
            Map session = ActionContext.getContext().getSession();
            session.put("logged-in", nombre_usuario);
            System.out.println("Usuario Metodo Accion: " + nombre_usuario + " contraseña: " + contrasenia);
            return redirect("/vistas/registrado/exitologin.jsp");
            } else {
            return redirect("/vistas/registrado/Login.jsp");
            }
        }
        return "success";
    }
    
    private String nombre_usuario;

    public String getNombre_usuario() {
        return nombre_usuario;
    }

    public void setNombre_usuario(String value) {
        nombre_usuario = value;
    }
    private String contrasenia;

    public String getContrasenia() {
        return contrasenia;
    }

    public void setContrasenia(String value) {
        contrasenia = value;
    }
}  

I've tried to substitute in Login.action

  if (logicaComun.login(nombre_usuario, contrasenia) == true)  

by

  if (nombre_usuario.equals("admin") && contrasenia.equals("admin"))  

and this way this action works fine and the rest keep showing the error. So I think maybe there is a problem with the session factory, but I can't see the problem in the configuration.

Thanks in advance.

[David Newton]

Without knowing what line the error message actually corresponds to it's difficult to help.

I don't see anywhere were you attempt to set logicaComun, though.

[Tony Manello]

The error line corresponds to this line of Login action class:

  if (logicaComun.login(nombre_usuario, contrasenia) == true)  

I forgot including the bussiness class LogicaComun:

 package Logica;

import org.springframework.transaction.annotation.Transactional;
import org.hibernate.SessionFactory;
import org.hibernate.Session;
import ObjetosDeNegocio.*;

@Transactional
public class LogicaComun {

    SessionFactory sessionFactory;

    public void setSessionFactory(SessionFactory value) {
        sessionFactory = value;
    }

    public Session sess() {
        return sessionFactory.getCurrentSession();
    }

    public boolean login(String nombre_usuario, String contrasenia) {
        System.out.println("Usuario: " + nombre_usuario + " Contraseña: " + contrasenia);
        Registrado registrado = (Registrado) sess().createQuery("SELECT r FROM Registrado r WHERE r.nombreUsuario = ?").setString(0, nombre_usuario).uniqueResult();
        if (registrado != null) {
            if (registrado.getNombreUsuario().equals(nombre_usuario) && registrado.getContrasenia().equals(contrasenia)) {
                return true;
            }
            return false;
        }
        return false;
    }
}   

When I try to use any method of the bussiness layer in an action in which is injected factory session, I get the error in the web browser.

LogicaComun (the bussiness layer or DAO), in the same way as session factory before, is injected to AccionBase action and it's Spring the responsible of injecting the bussiness sinlgeton in it.

All of this is the expected behaviour I understood from the tutorial, but I guess I'm wrong.

Any idea?

[David Newton]

But you *don't* inject it anywhere, that's what I'm saying. Where and how do you believe it's being set on the action?

[Tony Manello]

I understand what you say but now I'm so confused. According to this reference documentation is not need to set the reference by yourself because Spring's context do that with declared beans. So if I reference the bean "session factory" in the DAO LogicaComun with

 
# SessionFactory sessionFactory;  
#   
#     public void setSessionFactory(SessionFactory value) {  
#         sessionFactory = value;  
#     }    

and then I do the same with bean DAO in the Base Action (AccionBase)

 
#  protected LogicaComun logicaComun;  
#   
#     public void setLogicaComun(LogicaComun value) {  
#         logicaComun = value;  
#     }     

It should be ok shouldn't it?

What am I doing wrong?

Thanks for your patience!

[David Newton]

But your bean is named something else:

    <!-- Inject my business services class to the actions -->  
    <bean id="logica" class="Logica.LogicaComun" scope="singleton">  
        <property name="sessionFactory" ref="sessionFactory" />  
    </bean>  

I'm also assuming you're deploying the Struts 2 Spring plugin... although I don't actually know if it works with Spring 3 or not; I've never tried.

[Tony Manello]

I'm using Struts2 Spring plugin and it works at least with an example.

I changed the name reference for dependency injection in AccionBase from

  # #  protected LogicaComun logicaComun;    
# #     
# #     public void setLogicaComun(LogicaComun value) {    
# #         logicaComun = value;    
# #     }       

to

      protected LogicaComun logica;

    public void setLogica(LogicaComun value) {
        logica = value;
    } 

Now it seems to work OK. So as you said the problem was the bean name

Thanks a lot David!