錯誤使用Spring JSF 2.0休眠時初始化ManagedBean Maven

我正在使用JSF 2.0，Spring，Hibernate，並且遇到了ManagedBean初始化的問題。錯誤使用Spring JSF 2.0休眠時初始化ManagedBean Maven

以下是錯誤：

SEVERE: Error Rendering View[/cadastroDeProdutoAdminSistemas.xhtml] 
com.sun.faces.mgbean.ManagedBeanCreationException: Não é possível criar instância  para·a classe: com.catalogor3e.controller.PesquisaSistemasAdminBean. 
at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:193) 
at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:102) 
at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:409) 
at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:269) 
at com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:244) 
at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:116) 
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.AstIdentifier.getValue(AstIdentifier.java:72) 
at org.apache.el.parser.AstValue.getValue(AstValue.java:161) 
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:731) 
at org.primefaces.component.datatable.DataTable.getValue(DataTable.java:729) 
at org.primefaces.component.api.UIData.getDataModel(UIData.java:575) 
at javax.faces.component.UIData.getRowCount(UIData.java:356) 
at org.primefaces.component.datatable.DataTableRenderer.encodeTbody(DataTableRenderer.java:579) 
at org.primefaces.component.datatable.DataTableRenderer.encodeRegularTable(DataTableRenderer.java:220) 
at org.primefaces.component.datatable.DataTableRenderer.encodeMarkup(DataTableRenderer.java:192) 
at org.primefaces.component.datatable.DataTableRenderer.encodeEnd(DataTableRenderer.java:74) 
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875) 
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1764) 
at javax.faces.render.Renderer.encodeChildren(Renderer.java:168) 
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845) 
at org.primefaces.renderkit.CoreRenderer.renderChild(CoreRenderer.java:55) 
at org.primefaces.renderkit.CoreRenderer.renderChildren(CoreRenderer.java:43) 
at org.primefaces.component.layout.LayoutUnitRenderer.encodeEnd(LayoutUnitRenderer.java:51) 
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875) 
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1764) 
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1760) 
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1760) 
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1760) 
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:424) 
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:125) 
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121) 
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) 
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139) 
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:594) 
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) 
    Hibernate: select estado0_.id as id3_, estado0_.nome_estado as nome2_3_ from estado estado0_ 
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79) 
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
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:472) 
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:936) 
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) 
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) 
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004) 
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589) 
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312) 
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) 
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) 
at java.lang.Thread.run(Thread.java:722) 
     Caused by: java.lang.NullPointerException 
at com.catalogor3e.controller.PesquisaSistemasAdminBean.<init>(PesquisaSistemasAdminBean.java:51) 
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) 
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) 
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) 
at java.lang.reflect.Constructor.newInstance(Constructor.java:525) 
at java.lang.Class.newInstance0(Class.java:372) 
at java.lang.Class.newInstance(Class.java:325) 
at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:188) 
... 58 more

這裏是我的ManagedBean：

@ManagedBean(name="pesquisaSistemasAdminBean") 
@SessionScoped 
public class PesquisaSistemasAdminBean{ 

@ManagedProperty(value = "#{filtroEtiquetaCidadeSistemaBean}")  
private FiltroEtiquetaCidadeSistemaBean filtroEtiquetaCidadeSistemaBean; 

@ManagedProperty("#{facadeService}") 
private FacadeService service; 

private DataModel<Sistema> listaSistemas ; 

//variáveis para filtro 
private int idCategoriaParaFiltro = -1; 
private List<String> idsDeComponentesParaFiltro = new ArrayList<String>(); 
private int idFabricanteParaFiltro = -1; 


public PesquisaSistemasAdminBean() { 
    this.listaSistemas = new ListDataModel<Sistema> (this.service.getServiceSistemas().filtrarSistemaConstrutivo(null, null, null, null, null)); 
} 


//retorna todas as categorias(tipos) dos sistemas existentes no banco 
public List<CategoriaSistema> getListaDeCategorias(){ 
    List<CategoriaSistema> listaDeCategorias = this.service.getServiceCategoriaDeSistemas().getTodasAsCategoriasDeSistemas(); 
    return listaDeCategorias; 
} 

public void filtrarSistemaConstrutivo(){ 
    CategoriaSistema categoriaDeSistema = null; 
    Fabricante fabricante = null; 
    ZonaBioclimatica zona = null; 
    Etiqueta etiqueta = null; 
    List<CategoriaCamada> listaDeCategoriasDeComponentes = null; 
    if(this.idCategoriaParaFiltro != -1){ 
     categoriaDeSistema = this.service.getServiceCategoriaDeSistemas().getCategoriaPeloID(idCategoriaParaFiltro); 
    } 
    if(this.idFabricanteParaFiltro != -1){ 
     fabricante = this.service.getServiceFabricante().getFabricantePeloID(idCategoriaParaFiltro); 
    } 
    if(this.filtroEtiquetaCidadeSistemaBean.getZonaBioclimaticaParaFiltro() != null){ 
     zona = this.filtroEtiquetaCidadeSistemaBean.getZonaBioclimaticaParaFiltro(); 
    } 
    if(this.filtroEtiquetaCidadeSistemaBean.getIdEtiqueta() != -1){ 
     etiqueta = this.service.getServiceCidadeEstado().getEtiquetaPeloID(this.filtroEtiquetaCidadeSistemaBean.getIdEtiqueta()); 
    } 

    if(!this.idsDeComponentesParaFiltro.isEmpty()){ 
     listaDeCategoriasDeComponentes = new ArrayList<CategoriaCamada>(); 
     for(int i = 0; i < idsDeComponentesParaFiltro.size(); i++){ 
      CategoriaCamada categoriaCamada = this.service.getServiceCategoriaDeComponentesConstrutivos().getCategoriaComponenteConstrutivoPeloId(Integer.parseInt(idsDeComponentesParaFiltro.get(i))); 
      listaDeCategoriasDeComponentes.add(categoriaCamada); 
     } 
    } 
    this.listaSistemas = new ListDataModel<Sistema> (this.service.getServiceSistemas().filtrarSistemaConstrutivo(categoriaDeSistema, listaDeCategoriasDeComponentes, fabricante, zona, etiqueta)); 
} 

//retorna todos os fabricantes existentes no banco 
public List<Fabricante> getListaFabricantes(){ 
    List<Fabricante> listaDeFabricantes = this.service.getServiceFabricante().listaDeTodosOsFabricantes(); 
    return listaDeFabricantes; 
} 

///gets e sets está implementado, mas economizei código aqui!!!

，這裏是我的pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 
<modelVersion>4.0.0</modelVersion> 

<groupId>com.mycompany</groupId> 
<artifactId>catalogo</artifactId> 
<version>1.0-SNAPSHOT</version> 
<packaging>war</packaging> 

<name>catalogo</name> 

<properties> 
    <endorsed.dir>${project.build.directory}/endorsed</endorsed.dir> 
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 
</properties> 

<dependencies> 
    <dependency> 
<groupId>com.sun.faces</groupId> 
<artifactId>jsf-api</artifactId> 
<version>2.1.6</version> 
</dependency> 

    <dependency> 
    <groupId>com.sun.faces</groupId> 
    <artifactId>jsf-impl</artifactId> 
    <version>2.1.10</version> 
    </dependency> 

<dependency> 
    <groupId>javax.servlet</groupId> 
    <artifactId>jstl</artifactId> 
    <version>1.2</version> 
</dependency> 

<dependency> 
    <groupId>javax.persistence</groupId> 
    <artifactId>persistence-api</artifactId> 
    <version>1.0</version> 
</dependency> 

<dependency> 
     <groupId>org.springframework</groupId> 
     <artifactId>spring-test</artifactId> 
     <version>3.2.2.RELEASE</version> 
    </dependency> 
<dependency> 
    <groupId>org.springframework</groupId> 
    <artifactId>spring-core</artifactId> 
    <version>3.1.2.RELEASE</version> 
</dependency> 

<dependency> 
    <groupId>org.springframework</groupId> 
    <artifactId>spring-expression</artifactId> 
    <version>3.1.2.RELEASE</version> 
</dependency> 

<dependency> 
    <groupId>org.springframework</groupId> 
    <artifactId>spring-beans</artifactId> 
    <version>3.1.2.RELEASE</version> 
</dependency> 

<dependency> 
    <groupId>org.springframework</groupId> 
    <artifactId>spring-aop</artifactId> 
    <version>3.1.2.RELEASE</version> 
</dependency> 

<dependency> 
    <groupId>org.springframework</groupId> 
    <artifactId>spring-context</artifactId> 
    <version>3.1.2.RELEASE</version> 
</dependency> 

<dependency> 
    <groupId>org.springframework</groupId> 
    <artifactId>spring-context-support</artifactId> 
    <version>3.1.2.RELEASE</version> 
</dependency> 

<dependency> 
    <groupId>org.springframework</groupId> 
    <artifactId>spring-tx</artifactId> 
    <version>3.1.2.RELEASE</version> 
</dependency> 

<dependency> 
    <groupId>org.springframework</groupId> 
    <artifactId>spring-jdbc</artifactId> 
    <version>3.1.2.RELEASE</version> 
</dependency> 

<dependency> 
    <groupId>org.springframework</groupId> 
    <artifactId>spring-orm</artifactId> 
    <version>3.1.2.RELEASE</version> 
</dependency> 



<dependency> 
    <groupId>org.springframework</groupId> 
    <artifactId>spring-web</artifactId> 
    <version>3.1.2.RELEASE</version> 
</dependency> 

<dependency> 
      <groupId>org.hibernate</groupId> 
      <artifactId>hibernate</artifactId> 
      <version>3.2.6.ga</version> 
      <type>jar</type> 
     </dependency> 
     <dependency> 
      <groupId>org.hibernate</groupId> 
      <artifactId>hibernate-annotations</artifactId> 
      <version>3.3.1.GA</version> 
      <type>jar</type> 
     </dependency> 
     <dependency> 
      <groupId>org.hibernate</groupId> 
      <artifactId>hibernate-entitymanager</artifactId> 
      <version>3.3.2.GA</version> 
      <type>jar</type> 
     </dependency> 

<dependency> 
    <groupId>mysql</groupId> 
    <artifactId>mysql-connector-java</artifactId> 
    <version>5.1.15</version> 
</dependency> 


<dependency> 
    <groupId>org.slf4j</groupId> 
    <artifactId>slf4j-api</artifactId> 
    <version>1.6.1</version> 
</dependency> 

<dependency> 
    <groupId>org.slf4j</groupId> 
    <artifactId>slf4j-simple</artifactId> 
    <version>1.6.1</version> 
</dependency> 

<dependency> 
    <groupId>commons-collections</groupId> 
    <artifactId>commons-collections</artifactId> 
    <version>3.1</version> 
</dependency> 

<dependency> 
    <groupId>junit</groupId> 
    <artifactId>junit</artifactId> 
    <version>4.10</version> 
    <scope>test</scope> 
</dependency> 


<dependency> 
    <groupId>org.hibernate</groupId> 
    <artifactId>ejb3-persistence</artifactId> 
    <version>1.0.1.GA</version> 
</dependency> 

<dependency> 
    <groupId>javax.sql</groupId> 
    <artifactId>jdbc-stdext</artifactId> 
    <version>2.0</version> 
</dependency> 

<dependency> 
    <groupId>javax.transaction</groupId> 
    <artifactId>jta</artifactId> 
    <version>1.0.1B</version> 
</dependency> 

<dependency> 
    <groupId>org.primefaces</groupId> 
    <artifactId>primefaces</artifactId> 
    <version>3.4.1</version> 
</dependency> 

<dependency> 
    <groupId>org.primefaces.themes</groupId> 
    <artifactId>all-themes</artifactId> 
    <version>1.0.9</version> 
</dependency> 

<dependency> 
<groupId>commons-fileupload</groupId> 
<artifactId>commons-fileupload</artifactId> 
<version>1.2.3-SNAPSHOT</version> 
</dependency> 
<dependency> 
<groupId>commons-io</groupId> 
<artifactId>commons-io</artifactId> 
<version>2.5-SNAPSHOT</version> 
</dependency> 
<dependency> 
<groupId>rome</groupId> 
<artifactId>rome</artifactId> 
<version>1.0</version> 
</dependency> 
<dependency> 
<groupId>org.apache.poi</groupId> 
<artifactId>poi</artifactId> 
<version>3.7</version> 
</dependency> 
<dependency> 
<groupId>com.lowagie</groupId> 
<artifactId>itext</artifactId> 
<version>2.0.7</version> 
</dependency> 
    <dependency> 
     <groupId>javax</groupId> 
     <artifactId>javaee-api</artifactId> 
     <version>6.0</version> 
     <type>jar</type> 
    </dependency> 
    <dependency> 
     <groupId>javax</groupId> 
     <artifactId>javaee-web-api</artifactId> 
     <version>6.0</version> 
     <type>jar</type> 
    </dependency> 
</dependencies> 

<build> 
    <plugins> 
     <plugin> 
      <groupId>org.apache.maven.plugins</groupId> 
      <artifactId>maven-compiler-plugin</artifactId> 
      <version>2.3.2</version> 
      <configuration> 
       <source>1.6</source> 
       <target>1.6</target> 
       <compilerArguments> 
        <endorseddirs>${endorsed.dir}</endorseddirs> 
       </compilerArguments> 
      </configuration> 
     </plugin> 
     <plugin> 
      <groupId>org.apache.maven.plugins</groupId> 
      <artifactId>maven-war-plugin</artifactId> 
      <version>2.1.1</version> 
      <configuration> 
       <failOnMissingWebXml>false</failOnMissingWebXml> 
      </configuration> 
     </plugin> 
     <plugin> 
      <groupId>org.apache.maven.plugins</groupId> 
      <artifactId>maven-dependency-plugin</artifactId> 
      <version>2.1</version> 
      <executions> 
       <execution> 
        <phase>validate</phase> 
        <goals> 
         <goal>copy</goal> 
        </goals> 
        <configuration> 
         <outputDirectory>${endorsed.dir}</outputDirectory> 
         <silent>true</silent> 
         <artifactItems> 
          <artifactItem> 
           <groupId>javax</groupId> 
           <artifactId>javaee-endorsed-api</artifactId> 
           <version>6.0</version> 
           <type>jar</type> 
          </artifactItem> 
         </artifactItems> 
        </configuration> 
       </execution> 
      </executions> 
     </plugin> 
    </plugins> 
</build> 
<repositories> 


    <repository> 
     <url>http://download.java.net/maven/2/</url> 
     <id>jsf20</id> 
     <layout>default</layout> 
     <name>Repository for library Library[jsf20]</name> 
    </repository> 
    <repository> 
     <url>http://repo1.maven.org/maven2/</url> 
     <id>jstl11</id> 
     <layout>default</layout> 
     <name>Repository for library Library[jstl11]</name> 
    </repository> 
    <repository> 
     <id>prime-repo</id> 
     <name>PrimeFaces Maven Repository</name> 
     <url>http://repository.primefaces.org</url> 
     <layout>default</layout> 
    </repository> 


     <repository> 
      <releases> 
      <enabled>false</enabled> 
     </releases> 
     <snapshots> 
      <enabled>true</enabled> 
     </snapshots> 
     <id>apache.snapshots</id> 
     <name>Apache Snapshot Repository</name> 
     <url>https://repository.apache.org/content/repositories/snapshots</url> 
    </repository> 
</repositories>

這裏是我的網頁。 xml

<?xml version="1.0" encoding="UTF-8"?> 
<web-app version="3.0" 
    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-app_3_0.xsd"> 


<context-param> 
    <param-name>javax.faces.PROJECT_STAGE</param-name> 
    <param-value>Development</param-value> 
</context-param> 


<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>/faces/*</url-pattern> 
</servlet-mapping> 
<session-config> 
    <session-timeout> 
     30 
    </session-timeout> 
</session-config> 

<welcome-file-list> 
    <welcome-file>faces/index.xhtml</welcome-file> 
</welcome-file-list> 

<context-param> 
    <param-name>primefaces.THEME</param-name> 
    <param-value>bootstrap</param-value> 
</context-param> 

    <filter-mapping> 
    <filter-name>PrimeFaces FileUpload Filter</filter-name> 
    <servlet-name>Faces Servlet</servlet-name> 
    </filter-mapping> 
    <filter> 
    <filter-name>PrimeFaces FileUpload Filter</filter-name>  
    <filter-class>org.primefaces.webapp.filter.FileUploadFilter</filter-class> 
    </filter>  



    <context-param> 
    <param-name>contextConfigLocation</param-name> 
    <param-value>/WEB-INF/applicationContext.xml</param-value> 
    </context-param> 
<listener> 
    <listener-class> 
    org.springframework.web.context.request.RequestContextListener 
    </listener-class> 
</listener> 
<listener> 
    <listener-class> 
    org.springframework.web.context.ContextLoaderListener 
    </listener-class> 
</listener> 

</web-app>

，這裏是我的applicationContext.xml

<?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: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-3.0.xsd 
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-3.0.xsd 
    http://www.springframework.org/schema/tx 
    http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"> 

    <!-- Seta anotaçoes para serem <context:annotation-config />usadas pelo Spring --> 
    <context:annotation-config /> 


    <!-- Define o pacote onde o Spring vai procurar por beans anotados --> 
    <context:component-scan base-package="com.catalogor3e.dao, com.catalogor3e.service" /> 

    <!-- define que as transaçoes irao ser anotadas --> 
    <tx:annotation-driven /> 



<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> 
    <property name="driverClassName" value="com.mysql.jdbc.Driver"/> 
    <property name="url" value="jdbc:mysql://localhost:3306/bancodedados"/> 
    <property name="username" value="root"/> 
    <property name="password" value="852456"/> 
    </bean> 

< bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> 
     <property name="persistenceUnitName" value="catalogoPU" /> 
     <property name="dataSource" ref="dataSource" /> 
     <property name="jpaVendorAdapter"> 
      <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"> 
       <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect" /> 
       <property name="showSql" value="true" /> 
      </bean> 
     </property> 
</bean> 

<!-- Configuracao do gerente de transacoes do Spring --> 
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"> 
    <property name="entityManagerFactory" ref="entityManagerFactory" /> 
</bean> 

</beans>

請，任何人可以幫助我，好嗎？

ATT，

迭戈薩比諾

來源

2013-04-18 Diego Sabino

這裏是你的異常的根本原因，這是最底部。這是最相關的：

Caused by: java.lang.NullPointerException 
    at com.catalogor3e.controller.PesquisaSistemasAdminBean.<init>(PesquisaSistemasAdminBean.java:51)

那麼，什麼是null bean的構造函數中，而代碼試圖訪問/調用它。讓我們來看看構造函數：

public PesquisaSistemasAdminBean() { 
    this.listaSistemas = new ListDataModel<Sistema> (this.service.getServiceSistemas().filtrarSistemaConstrutivo(null, null, null, null, null)); 
}

嘿，你要訪問的聲明爲託管屬性service。您似乎期待託管財產注入工程如下：

PesquisaSistemasAdminBean pesquisaSistemasAdminBean; // Declare bean. 
pesquisaSistemasAdminBean.setService(facadeService); // Set service. 
pesquisaSistemasAdminBean = new PesquisaSistemasAdminBean(); // Invoke constructor.

但這是不可能的。從技術角度講，在構建實例之前，將服務設置爲實例變量是不可能的。事實上，以下是到底發生了什麼：

PesquisaSistemasAdminBean pesquisaSistemasAdminBean; // Declare bean. 
pesquisaSistemasAdminBean = new PesquisaSistemasAdminBean(); // Invoke constructor. 
pesquisaSistemasAdminBean.setService(facadeService); // Set service.

這就解釋了爲什麼該服務仍null在構造函數中。如果打算在bean構建之後直接執行基於注入依賴關係的業務邏輯，那麼您應該使用註釋方法@PostConstruct。

所以，你需要由@PostConstruct方法

@PostConstruct public void init() { this.listaSistemas = new ListDataModel<Sistema> (this.service.getServiceSistemas().filtrarSistemaConstrutivo(null, null, null, null, null)); }

的方法名稱是完全對您的選擇，順便更換構造

public PesquisaSistemasAdminBean() { 
    this.listaSistemas = new ListDataModel<Sistema> (this.service.getServiceSistemas().filtrarSistemaConstrutivo(null, null, null, null, null)); 
}

。

來源

2013-04-18 11:28:28 BalusC

嘿，非常感謝！這樣可行。這解決了我的問題。 – 2013-04-18 12:03:58

不客氣。 – BalusC 2013-04-18 12:06:53

BalusC你能幫助解決這個問題嗎？ http：// stackoverflow。com/questions/16083199/lazyinitialization -with-jpa-spring-hibernate-jsf-2-0 – 2013-04-18 12:44:55

錯誤使用Spring JSF 2.0休眠時初始化ManagedBean Maven

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