使用CDI注入FacesContext

我有我的豆子:

import java.io.Serializable;

import javax.enterprise.context.SessionScoped;
import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;
import javax.inject.Inject;
import javax.inject.Named;
import javax.persistence.EntityManager;

import br.com.dropper.web.dao.UsuarioDAO;
import br.com.dropper.web.model.Usuario;
import br.com.dropper.web.util.JpaUtil;

@Named
@SessionScoped
public class LoginBean implements Serializable {

    private static final long serialVersionUID = 1L;

    @Inject
    private FacesContext context;

    @Inject
    private Usuario usuario;


    //TODO: Persistencia e Transacao controladas por EJB
    private EntityManager em = new JpaUtil().getEntityManager();
    private UsuarioDAO usuarioDAO = new UsuarioDAO(em);



    public Usuario getUsuario() {
        return usuario;
    }

    public String autenticar() {

        Usuario usuario = usuarioDAO.obterUsuarioPorEmail(this.usuario);

        if (usuario == null) {
            context.addMessage(null, new FacesMessage("Usuario não encontrado."));
            context.getExternalContext().getFlash().setKeepMessages(true);
            return "login?faces-redirect=true";
        } else {
            context.getExternalContext().getSessionMap().put("usuarioLogado", usuario);
            return "dashboardImagem.xhtml?faces-redirect=true";
        }
    }

    public String cadastrarUsuario() {
        System.out.println("Redirecionando para cadastroUsuario.xhtml");
        return "cadastroUsuario.xhtml?faces-redirect=true";
    }

    public String logout() {
        context.getExternalContext().getSessionMap().remove("usuarioLogado");
        context.getExternalContext().invalidateSession();
        return "login.xhtml?faces-redirect=true";

    }

}

而我的工厂:

package br.com.dropper.web.factory;

import java.io.Serializable;

import javax.enterprise.inject.Produces;
import javax.faces.context.FacesContext;
import javax.faces.view.ViewScoped;

public class FacesContextFactory implements Serializable{

    private static final long serialVersionUID = 1L;

    @Produces
    @ViewScoped
    public FacesContext getFacesContext(){
        return FacesContext.getCurrentInstance();
    }

}

当我运行我的应用程序时,我得到这个例外:

Caused by: org.jboss.weld.exceptions.IllegalProductException: WELD-000053: Producers cannot declare passivating scope and return a non-serializable class: Producer for Producer Method [FacesContext] with qualifiers [@Any @Default] declared as [[BackedAnnotatedMethod] @Produces @ViewScoped public br.com.dropper.web.factory.FacesContextFactory.getFacesContext()] declared on Managed Bean [class br.com.dropper.web.factory.FacesContextFactory] with qualifiers [@Any @Default]
    at br.com.dropper.web.factory.FacesContextFactory.getFacesContext(FacesContextFactory.java:16)

当我将produce方法更改为@RequestScoped时,我的FacesContext只注入一次,而在我的第二页xhtml中,我得到一个nullpointer =(

更新:pom

    4.0.0
    br.com.dropper
    dropper-web
    0.1
    war

    
        
            
                javax
                javaee-api
                7.0
                provided
            
        
    

    

        
            javax
            javaee-api
            provided
        

        

        
            dropper-web
            bootstrap
            1.0.10
            system
            ${project.basedir}/src/main/webapp/WEB-INF/lib/bootstrap-1.0.10.jar
        

        
            dropper-web
            commons-io
            2.5
            system
            ${project.basedir}/src/main/webapp/WEB-INF/lib/commons-io-2.5.jar
        

        
            dropper-web
            cupertino
            1.0.10
            system
            ${project.basedir}/src/main/webapp/WEB-INF/lib/cupertino-1.0.10.jar
        


        
            dropper-web
            primefaces-6.0
            6.0
            system
            ${project.basedir}/src/main/webapp/WEB-INF/lib/primefaces-6.0.jar
        

    


    
        dropper-web
        
            
                org.apache.maven.plugins
                maven-compiler-plugin
                3.1
                
                    1.8
                    1.8
                
            
        
    

ATT

事实FacesContext本身并非如此Serializable.更重要的是,绝对不是 @ViewScoped.它实际上比实际上更短@RequestScoped,但是直到JSF 2.3发布,它带有改进的CDI支持,所以你可以在@Inject FacesContext没有自定义生产者的情况下,可以更少或更安全地使用它@Produces @RequestScoped.

@Produces
@RequestScoped
public FacesContext getFacesContext(){
    return FacesContext.getCurrentInstance();
}

这种情况仍然会失败的一种情况是当您使用RequestDispatcher#forward()或在同一请求中明确执行转发时ExternalContext#dispatch().然后,您将在com.sun.faces.context.FacesContextImpl.assertNotReleased中面对java.lang.IllegalStateException.然而,这是一种非常罕见的情况,通常只在设计糟糕的(ajax)异常处理程序中执行.另请参阅使用JSF错误处理程序中的ExternalContext.dispatch导致损坏的页面呈现.