每次我在JSF2中发出Ajax请求时，我都会得到一个新的会话bean，为什么？

问题描述

嗨我正在为这个Bean发出的每个ajax请求获得一个新的会话bean ...你们有没有告诉我为什么？

Hi I am getting a new session bean for every ajax request made to this Bean... Can any of you tell me why ?

...... imports ......
@Named(value = "userController")
@SessionScoped
public class UserController implements Serializable {

private User current;
private DataModel items = null;
@EJB
private br.com.cflex.itm.dataaccess.UserFacade ejbFacade;
private PaginationHelper pagination;
private int selectedItemIndex;

public UserController() {
}

public Collection<Project> getMyProjectList(){
    String login = FacesContext.getCurrentInstance().getExternalContext().getUserPrincipal().getName();
    User u = ejbFacade.getUserFromLogin(login);
    return u.getProjectCollection();
}    

public User getSelected() {               
    if (current == null) {
        current = new User();
        selectedItemIndex = -1;
    }
    return current;
} 
....... rest of class ....

每次我提出这个请求时，我都会得到一个新的SessionBean我知道我应该一遍又一遍地得到同一个人。

Every time I make this request I am getting a new of this SessionBean I for as far as I know I should be getting the same guy over and over again.

    <h:panelGrid columns="2" cellpadding="2">
      <h:form>
       <h:outputText value="#{bundle.FirstName}"/>                                
         <h:inputText id="name" value="#{userController.selected.name}">
          <f:ajax event="keyup" execute="name" render="out" />
<!--       <f:ajax event="keyup" render="out"/>-->
           </h:inputText>
           <p>
            <h:commandButton value="add"></h:commandButton>      
            <h:outputText id="out" value="#{userController.selected.name}"/>
           </p>
      </h:form>
    </h:panelGrid>

推荐答案

如果您意外导入来自包而不是 package。

That can happen if you accidently imported @SessionScoped from the javax.faces.bean package instead of the javax.enterprise.context package.

您正在使用注释，因此您应该从 javax.enterprise.context 包中导入范围。 javax.faces.bean 包中的范围仅与注释。

You're using @javax.inject.Named annotation, so you should import the scopes from the javax.enterprise.context package. The scopes from the javax.faces.bean package only works in combination with @javax.faces.bean.ManagedBean annotation.

没有有效范围的CDI bean的行为类似于 @RequestScoped 。没有有效范围的JSF bean的行为类似于 @NoneScoped 。

A CDI bean without a valid scope will behave like @RequestScoped. A JSF bean without a valid scope will behave like @NoneScoped.

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