Allen and I are getting ready to commit a fix for ROL-865
http://opensource2.atlassian.com/projects/roller/browse/ROL-865
This is a fairly big fix, so extra warning is needed. There are two
parts to the fix:
1) Apply "encapsulate members" refactoring to all POJOs so that all use
getters and setters to access members, even internally. This should
ensure that Hibernate lazy-loading will work, when it is in effect.
2) Upgrade to XDoclet 1.2.3 and add @hibernate.class lazy="false" to
all POJOs. This will revert our use of lazy-loading back to the way it
was in Roller 1.x, that is lazy-loading is off by default and turned on
explicitly for (most) collections.
- Dave
On Nov 2, 2005, at 1:34 PM, Dave Johnson wrote:
I'm going to go ahead and commit my changes to the POJOs. I added
lazy="false" to each class, but that will have no effect until I
commit XDoclet 1.2.3.
I'm holding off on committing XDoclet 1.2.3 in case somebody has a
last minute objection.
Any objections?
- Dave
On Nov 2, 2005, at 12:41 PM, Dave Johnson wrote:
On Nov 2, 2005, at 12:25 PM, Allen Gilliland wrote:
So it sounds like there are a couple options ...
1. alter our hibernate mappings to for lazy="false" by default.
this would require upgrading our xdoclet version.
2. alter our pojos to force the use of getters/setters and prevent
the use of direct accessors.
Assuming we've correctly identified the problem, #2 alone should
solve it.
personally, i think we should do both, but i would be more adamant
about doing #2. the standard pojo/bean pattern recommends that
attributes be private and only accessed through getters and setters
and i believe we should adhere to that. it seems pretty lame that
hibernate couldn't deal with direct access, but oh well. with a bit
of IDE wizardry it shouldn't be too hard to make this happen.
of course it also makes sense that we probably don't need to use
lazy loading on *all* pojo properties, so defaulting to lazy="false"
would be a good thing too. i don't know all the details about why
that was changed in hibernate 3, maybe there is a good reason to use
lazy loading all the time? maybe this would account for the
performance improvements you noted on your site Dave?
That's possible, I guess, but I really don't know the answer.
what does everyone else prefer to do?
I'd prefer to do both #1 and #2 right now, but could be talked into
saving #1 for later.
- Dave
-- Allen
On Wed, 2005-11-02 at 06:17, Dave Johnson wrote:
On Nov 2, 2005, at 7:44 AM, Dave Johnson wrote:
Anil wrote:
Changing the loading behavior in the mappings to be non-lazy one
should be able to avoid this behavior. If we have a lot of code
dealing with pojo members directly, we may want to do this. I
believe the laziness defaults changed between 2.x and 3.x.
The more involved fix is to upgrade to the latest XDoclet (which
may
require building it from CVS to get around that bug that bit me),
set
lazy="false" at the class level and set lazy="true" for the
individual
collections that we want to be lazy-loaded (and I think we're
already
doing that). We're using XDoclet 1.2b4 and the latest XDoclet is
1.2.
I've implemented that more involved fix in my workspace. I upgraded
to
XDoclet 1.2.3, found a reasonable work-around for that bug I
mentioned
and set lazy="false" at the @hibernate.class level for all 28 of our
POJOS. Roller appears to be working fine in my workspace.
There are three reasons why we might want to commit this for 2.0:
1) it solves the intermittent null problem (we need to verify this)
2) it's better to use an official release of XDoclet rather than
custom
1.2b4 build
3) it's better to stick with lazy="false" since that's what we were
doing before 2.0
Since I can't duplicate the intermittent null problem, Allen needs
to
verify that #1 is a true statement.
- Dave
