liste vide avec l'erreur java.lang.NullPointerException

**redoff** · 15/11/2015, 13h33

Bonjour tout le monde,

je travaille avec spring, hibernate et jsf (primefaces) ainsi que tomcat 7 et mysql (xampp et mysql workbench)
ma première page sert à afficher une liste retournée par une méthode et stockée par la variable "listDerivations" (qui a le getter et le setter).
tout d'abord voici l'architecture du projet.
Nom : architecture_projet.png
Affichages : 666
Taille : 22,1 Ko

Nom : architecture_projet.png
Affichages : 666
Taille : 22,1 Ko

et voici le code de mes différentes class et interface et fichiers de configuration

com.model.derivation

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package com.model;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.validation.constraints.NotNull;
 
@Entity
@Table(name="derivation") // nom de la table dans la base de données (sans majuscules)
public class Derivation {
	@Id
	@NotNull
	private int idderivation;
	@Column
	private int code_derivation;
	@Column
	private String libelle_derivation;
	@Column
	private int etat_derivation;
	// Constructeurs avec et sans arguments
	// Getters and Setters
}

com.service.DerivationService

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package com.service;
import java.util.List;
import com.model.Derivation;
public interface DerivationService {
	public List<Derivation> findAll();
}

com.service.DerivationServiceImpl

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package com.service;
import java.util.List;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.model.Derivation;
 
@Service("derivationService")
@Transactional
public class DerivationServiceImpl implements DerivationService {
	@Autowired
	private SessionFactory sessionFactory;
	@Override
	public List<Derivation> findAll() {
	return (List<Derivation>)this.sessionFactory.getCurrentSession().createQuery("from derivation").list();
	}
}

com.beans.DerivationBean

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package com.beans;
import java.util.ArrayList;
import java.util.List;
import javax.faces.bean.ManagedBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;
import com.model.Derivation;
import com.service.DerivationService;
 
@ManagedBean(name="derivationBean")
@Scope
public class DerivationBean {
	private List<Derivation> listDerivations = new ArrayList<Derivation>();
	@Autowired 
	private DerivationService derivationService;
 
	public List<Derivation> getListDerivations() {
		listDerivations = derivationService.findAll();
		//Derivation d = new Derivation();
		//d.setLibelle_derivation("test");
		//listDerivations.add(d);
		return listDerivations;
	}
	public void setListDerivations(List<Derivation> listDerivations) {
		this.listDerivations = listDerivations;
	}
}

application-context.xml

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<?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:context="http://www.springframework.org/schema/context"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd">
 
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
	<property name="driverClass" value="org.gjt.mm.mysql.Driver"></property>
	<property name="user" value="root"/>
	<property name="password" value=""/>
	<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/atgdb"></property>
</bean>
 
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
	<property name="dataSource" ref="dataSource"/>
	<property name="packagesToScan" value="com.model"/>
	<property name="hibernateProperties">
		<props>
			<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
			<prop key="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</prop>
		</props>
	</property>
</bean>
 
<bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
	<property name="sessionFactory" ref="sessionFactory"></property>
</bean>
 
<tx:annotation-driven transaction-manager="transactionManager"/>
<context:annotation-config/>
<context:component-scan base-package="com"></context:component-scan>
</beans>

web.xml

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<?xml version="1.0" encoding="ASCII"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
  <display-name></display-name>
 
  <context-param>
  	<param-name>contextConfigLocation</param-name>
  	<param-value>classpath:application-context.xml</param-value>
  </context-param>
 
  <listener>
  	<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <listener>
  	<listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
  </listener>
 
  <servlet>
  	<servlet-name>Faces Servlet</servlet-name>
  	<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
  	<load-on-startup>1</load-on-startup>
  </servlet>
 
  <servlet-mapping>
  	<servlet-name>Faces Servlet</servlet-name>
  	<url-pattern>*.xhtml</url-pattern>
  </servlet-mapping>
 
  <welcome-file-list>
    <welcome-file>listderivations.xhtml</welcome-file>
  </welcome-file-list>
 
  </web-app>

faces-config.xml

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<?xml version="1.0" encoding="UTF-8"?>
<faces-config
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
    http://java.sun.com/xml/ns/javaee/web-facesconfig_2_0.xsd"
    version="2.0">
 
    <application>
    	<el-resolver>org.springframework.web.jsf.el.SpringBeanFacesELResolver</el-resolver>
    </application>
</faces-config>

la page d'affichage listderivations.xhtml

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<html xmlns="http://www.w3.org/1999/xhtml"   
      xmlns:h="http://java.sun.com/jsf/html"
      xmlns:f="http://java.sun.com/jsf/core"
      xmlns:p="http://primefaces.org/ui"
      >
<h:head>
 
</h:head>
<h:body>
<h:outputLabel value="testaffichage"></h:outputLabel>
		<p:dataTable value="#{derivationBean.listDerivations}" var="derivation">
			<p:column headerText="Id Derivation">
				<h:outputText value="#{derivation.idderivation}"/>
			</p:column>
			<p:column headerText="Code Derivation">
				<h:outputText value="#{derivation.code_derivation}"/>
			</p:column>
			<p:column headerText="Libelle Derivation">
				<h:outputText value="#{derivation.libelle_derivation}"/>
			</p:column>
			<p:column headerText="Etat Derivation">
				<h:outputText value="#{derivation.etat_derivation}"/>
			</p:column>
		</p:dataTable>
</h:body>
</html>

quand je lance l'application, j'ai l'erreur suivante :

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nov. 15, 2015 1:30:58 PM com.sun.faces.application.view.FaceletViewHandlingStrategy handleRenderException
GRAVE: Error Rendering View[/listderivations.xhtml]
javax.el.ELException: /listderivations.xhtml @15,75 value="#{derivationBean.listDerivations}": Error reading 'listDerivations' on type com.beans.DerivationBean
	at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:114)
	at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
	at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)
	at javax.faces.component.UIData.getValue(UIData.java:732)
	at org.primefaces.component.api.UIData.getDataModel(UIData.java:759)
	at javax.faces.component.UIData.getRowCount(UIData.java:356)
	at org.primefaces.component.datatable.DataTableRenderer.encodeTbody(DataTableRenderer.java:806)
	at org.primefaces.component.datatable.DataTableRenderer.encodeTbody(DataTableRenderer.java:788)
	at org.primefaces.component.datatable.DataTableRenderer.encodeRegularTable(DataTableRenderer.java:281)
	at org.primefaces.component.datatable.DataTableRenderer.encodeMarkup(DataTableRenderer.java:243)
	at org.primefaces.component.datatable.DataTableRenderer.encodeEnd(DataTableRenderer.java:85)
	at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:924)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1863)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
	at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:443)
	at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
	at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
	at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
	at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)
Caused by: javax.el.ELException: Error reading 'listDerivations' on type com.beans.DerivationBean
	at javax.el.BeanELResolver.getValue(BeanELResolver.java:98)
	at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
	at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
	at org.apache.el.parser.AstValue.getValue(AstValue.java:183)
	at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:185)
	at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
	... 36 more
Caused by: java.lang.NullPointerException
	at com.beans.DerivationBean.getListDerivations(DerivationBean.java:30)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at javax.el.BeanELResolver.getValue(BeanELResolver.java:87)
	... 41 more
 
nov. 15, 2015 1:30:58 PM org.apache.catalina.core.StandardWrapperValve invoke
GRAVE: Servlet.service() for servlet [Faces Servlet] in context with path [/checkingatg] threw exception [null] with root cause
java.lang.NullPointerException
	at com.beans.DerivationBean.getListDerivations(DerivationBean.java:30)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at javax.el.BeanELResolver.getValue(BeanELResolver.java:87)
	at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
	at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
	at org.apache.el.parser.AstValue.getValue(AstValue.java:183)
	at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:185)
	at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
	at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
	at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)
	at javax.faces.component.UIData.getValue(UIData.java:732)
	at org.primefaces.component.api.UIData.getDataModel(UIData.java:759)
	at javax.faces.component.UIData.getRowCount(UIData.java:356)
	at org.primefaces.component.datatable.DataTableRenderer.encodeTbody(DataTableRenderer.java:806)
	at org.primefaces.component.datatable.DataTableRenderer.encodeTbody(DataTableRenderer.java:788)
	at org.primefaces.component.datatable.DataTableRenderer.encodeRegularTable(DataTableRenderer.java:281)
	at org.primefaces.component.datatable.DataTableRenderer.encodeMarkup(DataTableRenderer.java:243)
	at org.primefaces.component.datatable.DataTableRenderer.encodeEnd(DataTableRenderer.java:85)
	at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:924)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1863)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
	at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:443)
	at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
	at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
	at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
	at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)

je ne vois pas pourquoi l'erreur retourne que la liste est vide alors que la table "derivation" dans la bd contient 2 lignes.
merci à vous.

liste vide avec l'erreur java.lang.NullPointerException

Hibernate Java

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