为每个请求创建的jsf 2会话bean [英] jsf 2 Session bean created for every request

问题描述

你好

我有2个托管bean，一个View范围，另一个Session范围. View作用域bean定义为

I have 2 Managed beans, one View scoped, the other Session scoped. The View scoped bean is defined as

@ManagedBean
@ViewScoped
public class InvoiceController implements Serializable {
  private static final long serialVersionUID = 1L;

  @ManagedProperty(value="#{invoiceService}")
  private InvoiceService invoiceService;

会话作用域为

@ManagedBean
@SessionScoped
public class InvoiceService implements Serializable{

我正在使用会话范围的bean来保存用于决定是否应呈现面板的标志，当我通过调试运行此标志时，我发现每次我在sesison bean上调用该方法时，它都是一个新实例，因此在两次请求之间不保留我的标志的值.

I am using the session scoped bean to hold a flag used to decide if a panel should be rendered, when I run this through the debug I find that every time I call the method on the sesison bean, it is a new instance of the bean and therefore does not retain the value of my flag between requests.

我在做什么错了?

推荐答案

如果您是从 @Named bean，而后者适用于JSF @ManagedBean 仅限豆子.

That can happen if you have imported @SessionScoped from the javax.enterprise.context package instead of from the javax.faces.bean package. The former works on CDI @Named beans only, while the latter works on JSF @ManagedBean beans only.

没有任何有效范围的JSF @ManagedBean将默认为

A JSF @ManagedBean without any valid scope would default to @NoneScoped which means that it's newly constructed on every single EL expression referencing the bean, such as the @ManagedProperty. This explains the symptoms you're seeing.

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