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Endless Loop in EntityContainer #4
Description
It might be due to my special setup: I have something like class B extends A<Spatial>, whereas class A<T> extends EntityContainer<T>
The code in question is right in the constructor of the EntityContainer:
// Find out what the type parameter is
for( Type t = getClass().getGenericSuperclass(); t != null; ) {
if( t instanceof ParameterizedType ) {
ParameterizedType pt = (ParameterizedType)t;
if( pt.getRawType() == EntityContainer.class ) {
parameter = (Class)pt.getActualTypeArguments()[0];
break;
}
} else if( t instanceof Class ) {
t = ((Class)t).getGenericSuperclass();
} else {
t = null;
}
}
In my case t is instanceof ParameterizedType, but the RawType isn't EntityContainer.
I could get around this by adding t = ((Class)pt.getRawType()).getGenericSuperclass(); just before the first else-if, however that leads to a Cast Exception in parameter = .
For some reason, the rawType now is EntityContainer, however the ActualTypeArgument still is ParameterizedTypeImpl of class A<T>
Activity
MeFisto94 commentedon Sep 18, 2017
So what I did as a workaround/fix here is:
So what I changed are two things, the one is the already mentioned iteration just before the else if however that can be removed, since I discovered that further iterating until you are at EntityContainer leaves you with the ActualTypeArgument of
T.This is why the equality check has been changed to
if( pt.getRawType() instanceof Class && EntityContainer.class.isAssignableFrom(((Class)pt.getRawType())) ) {. That way it works for multiple-level inheritances and catches the Generic at the top-level.Another issue this solution has though is when you have multiple generic parameters like
class A<X, Y> extends EntityContainer<Y>, for which there might not really be an easy solution apart from maybe getting rid of Reflection (granted such a use-case is very rare though)pspeed42 commentedon Nov 17, 2018
Looking at this, I think I understand... but it's going to be very hard for me to test it without a test case. I can create one but not in this round of patches. Leaving this open to look at again after this round of baselining.