null index column for collection

sbroadbr · **Joined:** Wed Mar 08, 2006 1:08 pm **Posts:** 2

I have a very simple bean called LangString with fields for a Locale and a String. My problem occurs when I create a HashMap of them with the Locale as the key and I use a null Locale for default and/or language-neutral text. The HashMap does not complain about null keys and Hibernate successfully persists them to the database but will not read them back. Whenever I try, org.hibernate.persister.collection.AbstractCollectionPersister.readIndex() throws a "null index column for collection" exception.

Is there a way of telling Hibernate to allow null keys in Maps or will I have to create some kind of placeholder Locale for "language-neutral"?

Hibernate version:
3.1

Mapping documents:

Code:

   <class name="vdex.LangStringBag" >
      <id name="id" type="integer" column="langstringbag_id">
         <generator class="sequence">
            <param name="sequence">langstringbag_seq</param>
         </generator>
      </id>   
      <map name="langstrings" inverse="true" cascade="all-delete-orphan">
         <key column="langstringbag_id" />
         <map-key formula="language" type="locale" />
         <one-to-many class="vdex.LangString" />
      </map>
   </class>

   <class name="vdex.LangString" >
      <id name="id" type="integer" column="langstring_id">
         <generator class="sequence">
            <param name="sequence">langstring_seq</param>
         </generator>
      </id>
      <many-to-one name="owner" column="langstringbag_id" not-null="true" />
      <property name="language" type="locale" />
      <property name="string" type="text" />
   </class>

kgignatyev · **Posted:** Wed Mar 08, 2006 2:00 pm

I would suggest using placeholder which in reality is not a placeholder but real name for the default locale :)
It removes any ambiguity about what is default: French, Russian, Chinese? Just specify it explicitly and remove all the uncertainty

sbroadbr · **Joined:** Wed Mar 08, 2006 1:08 pm **Posts:** 2

Thanks for such a prompt reply, kgignatyev.

Unfortunately, your solution will make it impossible to represent Strings where the language is uncertain, not specified, or not applicable. Such situations will occur in my project so the locale must be retrieved as it was entered.
If Hibernate will absolutely not accept null Map keys, I'll just have to create a "" Locale for these cases and use it whenever setLanguage() is called with a null argument.