JSF View Scoped Bean Reconstructed Multiple Times [duplicate]

问题

I thought @ViewScoped was supposed to prevent the bean from being reconstructed while the user is on the same page... So why is my @ViewScoped JSf controller bean being created multiple times even before the action handler causes the browser to navigate away from that view?

Can anyone point me in the right direction here?

Here is my code:

The View (domain/edit.xhtml)

<h:form prependId="false">
    <h:inputText id="descriptionField" value="#{domainEdit.domain.description}" />
    <h:commandButton id="saveButton" value="save" action="#{domainEdit.save}" />
</h:form>

The ViewScoped controller (DomainEdit.java)

@Named("domainEdit")
@ViewScoped
public class DomainEdit implements Serializable {

    private static final long serialVersionUID = 1L;


    protected DomainEdit() {
    }

    @PostConstruct
    protected void init() {
        System.out.println("post construct called.");
    }

    @PreDestroy
    public void destroy() {
        System.out.println("pre destroy called.");
    }

    public DomainEntity getDomain() {
        System.out.println("displaying domain...");

        // some code to return the domain
        return domain;
    }

    public String save() {
        System.out.println("saving...");

        // some saving code

        return "view";
    }
}

Output

I get the following output when I deploy this and perform the following:

Navigate to the edit view (edit.xhtml)

   post construct called.
   displaying domain...
   pre destroy called.

Change the content of the domainDescriptionField input text

nothing logged
Click 'save'

  post construct called.
  displaying domain...
  pre destroy called.

  post construct called.
  displaying domain...
  pre destroy called.

  post construct called.
  displaying domain...
  pre destroy called.

  post construct called.
  displaying domain...
  pre destroy called.

  post construct called.
  displaying domain...
  saving domain...
  pre destroy called.

回答1:

Unless you're using JSF 2.2 (which is still not out yet at this moment) or MyFaces CODI (which I'd have expected that you would explicitly mention that), the @ViewScoped doesn't work in CDI. This also pretty much matches your problem symptoms.

Manage the bean by JSF instead of CDI. Replace @Named("domainEdit") by @ManagedBean from javax.faces.bean package. Or, install MyFaces CODI to bridge JSF @ViewScoped to CDI.

来源：https://stackoverflow.com/questions/14812238/jsf-view-scoped-bean-reconstructed-multiple-times

标签

jsf

java-ee

ejb

view-scope