JSF 2.0和参数化EL表达式的问题

Question

I'm encountering some troubles while trying to access some properties with parameters. Well, I don't know if they should be called properties since the accessors have parameters but lets call them properties for now.

The situation is this:

I have a Student class that contains different localizations as objects in a map. I can get those localization objects by doing this:

student.getLocalizedData(String localizationCode);

Now, on the page, I'm trying to do this:

<h:inputText value="#{collegeBean.student.getLocalizedData('es').profileDescription}"/>

A student's description can have many localizations.

The page loads correctly, but when I try to save the student it says that the bean collegeBean does not have the property getLocalizedData, tough that one is a property of the student contained on the bean.

I know that line is insane, so I tried to wrap it:

<h:inputText value="#{collegeBean.getStudentLocalizedData('es').profileDescription}"/>

Alas, again I get the same message.

The only solution I've found is to make a method that completely wraps the studen't sproperty... but that leaves me with 2 methods (get + set) for every localization, and that's only for one property. This means that I'll end having (2 x localizations x attributes) amount of methods!.

Is there any approach I can take to solve this in the most dynamic way? The ammount of localizations might change in the future and I don't want to change any code.

EDIT: I'm using JBoss 6.1.0.Final and the JSF implementation that comes with it JSF 2.0.3-b05

Answer 1

This should theoretically work, so I suspect a bug or an oversight in the EL implementation used. You might want to try a different EL implementation (a different server make) or to upgrade the server. If in vain, report it as a bug to the server vendor.

However, since you're actually delegating the getLocalizedData() to a Map , better is to not do that but instead return the whole Map directly.

public Map<String, LocalizedData> getLocalizedData() {
    return localizedData;
}

so that you can use it as follows

<h:inputText value="#{collegeBean.student.localizedData.es.profileDescription}"/>

or, if desired

<h:inputText value="#{collegeBean.student.localizedData['es'].profileDescription}"/>

Answer 2

In my experience, most EL implementations that accept parameters are buggy in one way or other. The one I am most happy with is Tomcat 7's EL.

Note that you can use a custom EL implementation with Mojarra and MyFaces. I usually bundle Tomcat's one with my applications, so I can trust in a stable feature set being available. You must be careful though, as you can get into classloader problems if you don't configure everything correctly.

Mojarra:

<context-param>
    <param-name>com.sun.faces.expressionFactory</param-name>
    <param-value>YOUR EL IMPLEMENTATION EXPRESSION FACTORY</param-value>
</context-param>

MyFaces:

<context-param>
    <param-name>org.apache.myfaces.EXPRESSION_FACTORY</param-name>
    <param-value>YOUR EL IMPLEMENTATION EXPRESSION FACTORY</param-value>
</context-param>