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

Question

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>

@FrantisekKossuth: The code provided here is already narrowed down in order to contain as few error sources as possible. In the complete class, when the empty constructor is called (as for the case of the managed bean), the language is determined from the current locale in the context. When I need a custom translator somewhere in the code, I use the contructor with the language as argument. If you want to pass a variable to the managed bean, you have to declare a "managed-property" in your faces-config.xml . — xpages-noob
My question was EXACTLY about what you found (and commented below accepted answer) - you had to call init() somewhere... — Frantisek Kossuth

Jesse Gallagher Jesse Gallagher · Accepted Answer · 2014-07-23T01:10:51

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

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

2 Answers