CODEWITHSUNDEEP
xpages
xpages-noob
xpages-noob

Reputation: 1579

Managed Java bean gets re-initialized at EVERY complete refresh or page reload

In my XPages application, I use a managed Java bean (scope = application) for translating strings:

public class Translator extends HashMap<String,String> implements Serializable {

    private static final long serialVersionUID = 1L;
    public String language = "en";

    public Translator() { super(); this.init(null); }
    public Translator(String language) { super(); this.init(language); }

    public boolean init(String language) {
        try {           
            FacesContext context = FacesContext.getCurrentInstance();
            if (language!=null) this.language=language;
            Properties data = new Properties();

            // load translation strings from properties file in WEB-INF
            data.load(new InputStreamReader(context.getExternalContext().getResourceAsStream("WEB-INF/translations_"+this.language+".properties"),"UTF-8"));
            super.putAll(new HashMap<String,String>((Map) data));

            // serializing the bean to a file on disk > this part of the code is just here to easily test how often the bean is initialized
            ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("C:\\dump\\Translator_"+this.language+"_"+new Date().getTime()+".ser"));
            out.writeObject(this);
            out.close();

            return true;
        }
        catch (Exception e) { return false; }
    }

    public String getLanguage() { return this.language; }
    public boolean setLanguage(String language) { return this.init(language); }

    // special get function which is more tolerant than HashMap.get
    public String get(Object key) {
        String s = (String) key;
        if (super.containsKey(s)) return super.get(s);
        if (super.containsKey(s.toLowerCase())) return super.get(s.toLowerCase());
        String s1 = s.substring(0,1);
        if (s1.toLowerCase().equals(s1)) {
            s1=super.get(s1.toUpperCase()+s.substring(1));
            if (s1!=null) return s1.substring(0,1).toLowerCase()+s1.substring(1);
        } else {
            s1=super.get(s1.toLowerCase()+s.substring(1));
            if (s1!=null) return s1.substring(0,1).toUpperCase()+s1.substring(1);           
        }
        return s;
    }
}

I use "extends HashMap" because in this way i only have to write "${myTranslatorBean['someText']}" (expression language) to get the translations into my XPage. The problem is that the bean is re-initialized at EVERY complete refresh or page reload. I tested this by serializing the bean to a unique file on the disk at the end of every initialisiation. In my other managed Java beans (which do not use "extends HashMap") this problem does not occur. Can anybody tell me what's wrong with my code? Thanks in advance.


EDIT: The entry for the managed Java bean in the faces-config.xml looks like this:

  <managed-bean>
    <managed-bean-name>myTranslatorBean</managed-bean-name>
    <managed-bean-class>com.ic.Translator</managed-bean-class>
    <managed-bean-scope>application</managed-bean-scope>
  </managed-bean>

Upvotes: 0

Views: 656

Answers (2)

Jesse Gallagher
Jesse Gallagher

Reputation: 4471

I concur with David about the faces-config entry - if you could post it, that could shine some light on it.

In its absence, I'll take a stab at it: are you using a managed property to set the "language" value for the app. If you are, I suspect that there's a high chance that the runtime calls the setLanguage(...) method excessively. Since you call this.init(...) in that method, that would re-run that method repeatedly as well.

As a point of code style you are free to ignore, over time I (in part due to reading others' opinions) have moved away from extending collection classes directly for this kind of use. What I do instead in this situation is create an object that implements the DataObject interface and then uses a HashMap internally to store cached values. That's part of a larger industry preference called "Composition over inheritance": http://en.wikipedia.org/wiki/Composition_over_inheritance

Upvotes: 2

David Leedy
David Leedy

Reputation: 3593

Just to make sure nothings weird - I suggest you post your faces-config. I use beans all the time but haven't extended HashMap in any of them. You can add a map and still use EL.

Assuming you have a map getter like "getMyMap()" then EL might be:

AppBean.myMap["myKey"]

Truth be told I don't typically use that syntax but I BELIEVE that works. I gave it a quick test and it didn't work as I expected so I'm missing something. I tried something like: imageData.size["Large"].url

I THINK it didn't work for me because my bean doesn't IMPLEMENT Map. I notice you're EXTENDING HashMap. You might want to try implementing it. I found an interesting post here: http://blog.defrog.nl/2012/04/settings-bean-parameterized-method-call.html

Usually I do still use SSJS to pass Parameters in. It's really not the end of the would using SSJS for that. And I use EL for everything else.

This is an example of passing an object to a custom control and return a TreeSet with EL.

value="#{compositeData.imageSet.allImages}">

Regarding the bigger issue of the bean re-initializing.. That is odd.. I don't do a ton with ApplicationScope. But I suggest you play with the constructor. I'm not sure what you get by calling super() there. I would suggest use a boolean to only run any init code of the boolean wasn't already set. Obviously you then set it in the init code. See what that does.

Upvotes: 1

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