如果所有属性都是密钥的一部分，为什么hibernate的getPropertyNames返回一个空列表？

Question

Here's a fun head-scratcher to start the month of May off!

I have a hibernate mapping like so:

<hibernate-mapping default-lazy="false">
  <class name="my.class.name" table="MY_CLASS_TABLE">
     <composite-id>
       <key-property name="prop1" column="PROP_1" />
       <key-property name="prop2" column="PROP_2" />
       <key-property name="prop3" column="PROP_3" />
     </composite-id>
   </class>
</hibernate-mapping>

And a function that goes through and builds a "dictionary" of class names and properties. I have no problems until I get to this class, and for some reason, my call to getPropertyNames() returns an empty list. If there is at least one property outside the composite-id , I don't have any problems. The kludgy work-around I have is to add a dummy field outside the id (yuck!) and suddenly everything works.

Any idea why this is happening and what I can do to solve it?

Thanks in advance for your help!

Answer 1

After further digging, I found getIdentifierType() and getIdentifierPropertyName() do the job. For a composite key like this one, I check the type to see if it's an instance of CompositeCustomType or ComponentType, and if it is, throw it into a temporary var, and call getPropertyNames() on that temporary var.