Injecting ResourceBundle via @ManagedProperty doesn't seem to work inside @Named

Question

How can I access messages bundle from java code to get message according to current locale?

I tried using @ManagedProperty like below:

@         


        

Answer 1

You can't use @javax.faces.bean.ManagedProperty in a CDI managed bean as annotated with @Named. You can only use it in a JSF managed bean as annotated with @ManagedBean.

You need use @javax.faces.annotation.ManagedProperty instead, along with an @Inject. This was introduced in JSF 2.3.

@Inject @javax.faces.annotation.ManagedProperty("#{msg}")
private ResourceBundle bundle;

Noted should be that this gets injected as a @Dependent. So be aware that when you inject this into a @SessionScoped bean, then it would basically become @SessionScoped too and thus stick to the originally injected value forever. So any potential locale changes later on in the session won't be reflected there. If this is a blocker, then you should really inject it into a @RequestScoped or @ViewScoped only, or make use of a @Producer as shown below.

CDI doesn't have native annotations to inject the evaluation result of an EL expression. The CDI approach is using a "CDI producer" with @Produces wherein you return the concrete type, which is PropertyResourceBundle in case of .properties file based resource bundles.

So, if you cannot upgrade to JSF 2.3, then just drop this class somewhere in your WAR:

@RequestScoped
public class BundleProducer {

    @Produces
    public PropertyResourceBundle getBundle() {
        FacesContext context = FacesContext.getCurrentInstance();
        return context.getApplication().evaluateExpressionGet(context, "#{msg}", PropertyResourceBundle.class);
    }

}

With this, can inject it as below:

@Inject
private PropertyResourceBundle bundle;

Answer 2

In addition to BalusC's answer:

Since JSF 2.3 it is also possible to inject a resource bundle defined in faces-config.xml without the use of a producer method. There is a new annotation javax.faces.annotation.ManagedProperty (note it is in the ...annotation package, not the ...bean package) that works with @Inject:

// ...
import javax.faces.annotation.ManagedProperty;
// ...

@Named 
@SessionScoped 
public class UserBean implements Serializable {

  // ...

  @Inject
  @ManagedProperty("#{msg}")
  private ResourceBundle bundle;

  // ...

}

Answer 3

Perhaps I'm getting something wrong, but actually neither of the solutions provided worked for my use case. So I'm providing another answer that worked for me.

With the answer provided by BalusC I encountered the following problems:

• As I'm using ajaxbased validation, my beans are @ViewScoped, and must be serializable. As neither ResourceBundle nor PropertyResourceBundle are serializable they can't be injected with @Dependent scope.

• If I try to change the producer to use @RequestScoped it also fails because ResourceBundle is not proxyable as it defines final methods.

As I'm using JSF 2.3 (JBoss 7.2EAP) I went with the solution provided by Jören Haag and initially it seemed to work. Like the original question, I also have multiple supported locales, and the user can change between locales (in my case ca and es)

The problems I faced with Jören answer are

• The ResourceBundle returned is evaluated when the bean is created. In his example he is using a @SessionScoped bean. The ResourceBundle will be resolved with the current locale when the session is created. If the user later changes the locale, the ResourceBundle will not get updated. This also happens with @ViewScoped beans if the user can change the language without changing the view.

• I also encountered another issue with beans that need to preload data with a <f:viewAction>. In this case, the bean is instantiated earlier, so the ResourceBundle gets injected before the user locale is set with <f:view locale="#{sessionBean.locale}">. So If the user browser is using es, but the user changed the locale to ca, the bundle will be loaded with es instead, because the view locale is not set to ca with the sessionBean.locale until the render phase.

To overcome this issues that's the solution that worked for me for the use case of the question using injection would be:

@SessionScoped
public class UserBean implements Serializable {

    @Inject
    @ManagedProperty("#{msg}")
    private Instance<ResourceBundle> bundle;

    // ....

    public void someAction() {
        String message = bundle.get().getString("someLabel");
        // ...
    }

}

As the original question doesn't require injection, only asks how to access a resource bundle with the current locale, a solution without injection, and without the overhead of evaluating EL expression #{msg} every time bundle.get() is called would be:

@SessionScoped
public class UserBean implements Serializable {

    @Inject
    private FacesContext context;

    // ...

    public void someAction() {
        ResourceBundle bundle = context.getApplication().getResourceBundle(context, "msg");
        String message = bundle.getString("someLabel");
        // ...
    }

}