Jeff,
Thanks for the reply. I know not everyone likes the immutable pattern,
but I have found it tremendously useful and cuts down on a lot of
synchronized behavior because it creates thread-safe access. I am not
promoting its use for everything, but because I have quite a few classes
which do this, I have constantly found this a problem when using iBATIS.
How would a ResultObjectFactory solve this problem? I read up on it, but
can you give me exactly what you're thinking?
Thanks,
Paul
Jeff Butler wrote:
First thought - ugh. I really don't care for domain classes being
built this way. We did it once and it really didn't solve anything.
If a programmer wants to break the immutability, it is a simple matter
to cast the interface to the mutable implementation. So it's just a
lot of hassle for no benefit. (BTW - I know this is promoted in the
Sun blueprints catalog, but I still think it's awful. But that's just
my 2 cents - YMMV)
Second thought - if you really want to do this, you can code a
ResultObjectFactory and supply the concrete implementations yourself.
Jeff Butler
On 1/14/07, *Paul Benedict* <[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>> wrote:
I have this problem currently in iBATIS 2. I would prefer it be solved
in 2.4, but if it is more extensive in scope, then I wouldn't mind
seeing it pushed off to version 3.
Here are two classes which have two immutable interfaces:
interface A { class AImpl implements A {
String getName(); String getName();
} void setName(String name);
}
interface B { class BImpl implements B {
A getA(); A getA();
} void setA(A a);
}
At the moment iBATIS cannot create a BImpl because the get/setA
methods
are returning the interface signature (not the concrete mutable
class).
Even though iBATIS will call setA with an AImpl, it forgets the
implementation and cannot find setName on the returned object.
However, I think iBATIS CAN solve this problem!!! It's very easy: the
mapper needs to remember the concrete implementation injected, and
cast
that when calling the setter.
The only way to currently solve this problem is by altering the
class to
do this below. Here I have provided a separate set of properties just
for iBATIS object construction. It's not pretty but it's the only way
for iBATIS to "remember" the concrete type injected:
class BImpl implements B {
A getA();
void setA(A a);
AImpl getAImpl();
void setAImpl(AImpl);
}
Thoughts?
Paul
