Struts 2 + JPA

28 de abril de 2008 4 respostas

danielti 28 de abril de 2008

Pessoal,

Não consigo resolver este erro:

java.lang.NullPointerException
at mapIntelligence.ListaUsuariosAction.execute(ListaUsuariosAction.java:20)

Fonte da Classe:

package mapIntelligence;

import java.util.List;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionSupport;

public class ListaUsuariosAction extends ActionSupport{

private UsuarioImpl servico;

private List usuarios;

public ListaUsuariosAction() {

}
 public ListaUsuariosAction(UsuarioImpl servico) {  
       servico = servico;
 }
 public String execute() throws Exception {
       usuarios = servico.listarUsuarios();
      return Action.SUCCESS;

 }

}

UsuarioImpl :

package mapIntelligence;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

public class UsuarioImpl implements UsuarioIF{
private UsuarioDAO usuarioDAO;

public UsuarioImpl() {
}

public UsuarioImpl(UsuarioDAO usuarioDAO) {
      this.usuarioDAO = usuarioDAO;
}

public Usuario acharUsuario(Long id) {
      return usuarioDAO.acharUsuario(id);
}
public List<Usuario> listarUsuarios() {
      List<Usuario> lista = new ArrayList<Usuario>();
      List<Usuario> lista2 = usuarioDAO.obtemListaUsuario();
      if(lista2 != null) {
            lista.addAll(lista2);
      }
      return lista;
}



public void removerUsuario(Long id) {

      usuarioDAO.removerUsuario(id);

}

public void salvarUsuario(Usuario usuario) {

      usuarioDAO.adiciona(usuario);

}



public void removerUsuarios() {

      usuarioDAO.removeUsuarios();

}

public UsuarioDAO getUsuarioDAO() {
	return usuarioDAO;
}

public void setUsuarioDAO(UsuarioDAO usuarioDAO) {
	this.usuarioDAO = usuarioDAO;
}

}

struts.xml :

<?xml version="1.0" encoding="ISO-8859-1"?>

<package name="usuario" extends="struts-default">

/index.jsp /welcome.jsp /erroLogin.jsp /usuario.jsp /usuario.jsp /listaUsuarios.jsp /erroServicoUsuario.jsp /usuario.jsp /erroServicoUsuario.jsp /usuario.jsp

</package>

aplcationContext.xml:

<?xml version="1.0" encoding="ISO-8859-1"?>

<bean
    class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />

<bean id="dataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="com.mysql.jdbc.Driver" />
    <property name="url" value="jdbc:mysql://teste/teste" />
    <property name="username" value="teste" />
    <property name="password" value="teste" />
</bean>

<tx:annotation-driven transaction-manager="transactionManager" />

Se alguém puder me ajudar vai ser bom, pois estou tentando aprender struts 2 + JPA e encalhei aqui.
Detalhe:

Tenham paciência por favor, porque ainda estou aprendendo.

Obrigado,

4 Respostas

soudaniel_01 28 de abr. de 2008

na sua classe ListaUsuarioAction

faça isso

private UsuarioImpl servico = new UsuarioImpl() ;

depois veja o porque não está sendo injetado pelo spring…

danielti 28 de abr. de 2008

Oi Daniel,

O erro ainda persiste…

Obrigado,

Tecnoage 28 de abr. de 2008

poste seu cídogo com as tags “code”, fica mais fácil de ler.

Vc está mapeando suas classes de serviço com nomes diferentes no código da action e no spring… Verifique isso q vai funcionar.

danielti 28 de abr. de 2008

struts.xml:

<?xml version="1.0" encoding="ISO-8859-1"?>
<!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.objectFactory" value="spring" />
    <constant name="struts.devMode" value="true" />

    <package name="usuario" extends="struts-default">

         
<action name="login!*" method="{1}" class="mapIntelligence.LoginAction">
      <result name="input">/index.jsp</result>
      <result name="valido">/welcome.jsp</result>
      <result name="invalido">/erroLogin.jsp</result>
</action>
           
<action name="insereUsuario" class="mapIntelligence.InsereUsuarioAction">
      <result name="input">/usuario.jsp</result>
      <result>/usuario.jsp</result>
</action>

<action name="listaUsuarios"  class="mapIntelligence.ListaUsuariosAction">     
      <result>/listaUsuarios.jsp</result>
</action>

<action name="removerUsuario!*" method="removeLista"  class="mapIntelligence.RemoverUsuarioAction">
      <result name="erroServicoUsuario">/erroServicoUsuario.jsp</result>
      <result>/usuario.jsp</result>
</action>
        
<action name="removerUsuario!*" method="removeUmUsuario"   class="mapIntelligence.RemoverUsuarioAction">
      <result name="erroServicoUsuario">/erroServicoUsuario.jsp</result>
      <result>/usuario.jsp</result>
</action>

applicationContext.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<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-2.0.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd">

    <bean
        class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />

    
 
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="persistenceUnitName" value="punit"></property>
    <property name="dataSource" ref="dataSource"></property>
    <property name="jpaDialect">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect"></bean>
    </property>
    <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
                  <property name="database" value="MYSQL"></property>
                  <property name="showSql" value="true"></property>
                  <property name="generateDdl" value="true"></property>
            </bean>
      </property>
</bean>

    <bean id="dataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://teste/teste" />
        <property name="username" value="teste" />
        <property name="password" value="teste" />
    </bean>

<bean id="transactionManager"                                     class="org.springframework.orm.jpa.JpaTransactionManager">
      <property name="entityManagerFactory" ref="entityManagerFactory"></property>
      <property name="dataSource" ref="dataSource"></property>
</bean>

    <tx:annotation-driven transaction-manager="transactionManager" />

 <bean id="loginDao" class="mapIntelligence.LoginDAO">
      <constructor-arg ref="entityManagerFactory"></constructor-arg>
</bean>   

<bean id="usuarioDao" class="mapIntelligence.UsuarioDAO">
       <constructor-arg ref="entityManagerFactory"></constructor-arg>
</bean>
    
<bean id="servicoLogin" class="mapIntelligence.LoginImpl" scope="singleton">
      <property name="loginDAO" ref="loginDao"></property>
</bean>    

<bean id="servicoUsuario" class="mapIntelligence.UsuarioImpl" scope="singleton">
      <property name="usuarioDAO" ref="usuarioDao"></property>
</bean>    
    
<bean id="login" class="mapIntelligence.LoginAction" scope="prototype">
      <property name="servico" ref="servicoLogin"></property>
</bean>    


 <bean id="removeUsuario" class="mapIntelligence.RemoverUsuarioAction"   scope="prototype">
         <property name="servico" value="servicoUsuario"></property>
</bean>

 <bean id="insereUsuario" class="mapIntelligence.InsereUsuarioAction"   scope="prototype">
         <property name="servico" value="servicoUsuario"></property>
</bean>

 <bean id="listaUsuarios" class="mapIntelligence.ListaUsuariosAction"   scope="prototype">
         <property name="servico" value="servicoUsuario"></property>
</bean>


</beans>

Desculpe-me, mas não entendi. VocÊ poderia me mostrar um exemplo do que estou fazendo errado?

Muito obrigado,

Criado 28 de abril de 2008

Ultima resposta 28 de abr. de 2008

Respostas 4

Participantes 3

4 Respostas

Topicos relacionados