On 6/6/06, Andrus Adamchik <[EMAIL PROTECTED]> wrote:
On Jun 5, 2006, at 7:34 PM, Tomi NA wrote:
> How would this provide more information than monitoring
> setToObjectGroup() execution? Where is writeProperty used outside of
> the setters?
The framework can access objects bypassing the setters (e.g. this is
how Generic Persistent Class operates [1], but this is also true for
any DataObject).
So since I don't know how your code is written, I am making general
assumptions going from Cayenne end. There are two suspects. First is
that the relationship is nullified indirectly by Cayenne in response
to a sequence of events in the application. One more level down this
path - can you try putting a thread dump in 'writePropertyDirectly'
overriden method and see if it shows anything.
Second is that serialization is somehow involved, as deserialization
accesses fields directly.
These are the two ways to bypass the setters. Otherwise I am out of
ideas (without looking at the code that is).
I've narrowed the problem down and now that I've done it, I can't
believe what I'm seeing.
I noticed that the problem occurs when I run my "advanced search".
Once I run it, I can isolate an object (just one of many) whose
relations have been set to null. I then proceeded to
System.out.println(object.getToGroup().getToGroupCluster().getName())
debugging, for reasons that are unlikely to become obvious at the
moment.
The idea of the code snippet is to fill the objList List with all
instances of level 1 objects, something along the lines "for the given
level4 object, get all level3 objects and for every level3 object get
all level2 objects and for all level2 objects, get all level 1
objects."
Now, the debug statements inserted like this don't throw a
java.lang.NullPointerException:
List<Level3Object> level3Objects =
criteria.getLevel4Object().getLevel3ObjectArray();
for (Level3Object u : level3Objects) {
List<Level2Object> level2Objects = u.getLevel2ObjectArray();
// 2 DEBUGGING STATEMENTS:
Level1Object l1o = (Level1Object)
DataObjectUtils.objectForPK(context, Level1Object.class, 31332);
System.out.println(l1o.getToLevel2Object().getToLevel3Object().getName());
for (Level2Object l2o : level2Objects) {
objList.add(l2o);
}
}
However, when I move the two debugging statements into the following
for-loop, I get the NullPointerException on the
System.out.println(...) because getLevel3Object() is null and
therefore can't call it's getName() method:
List<Level3Object> level3Objects =
criteria.getLevel4Object().getLevel3ObjectArray();
for (Level3Object u : level3Objects) {
List<Level2Object> level2Objects = u.getLevel2ObjectArray();
for (Level2Object l2o : level2Objects) {
Level1Object l1o = (Level1Object)
DataObjectUtils.objectForPK(context, Level1Object.class, 31332);
System.out.println(l1o.getToLevel2Object().getToLevel3Object().getName());
objList.add(l2o);
}
}
I can't for the life of me guess what the final for-loop does that
nullifies the relevant object relationship.
t.n.a.
