generic Map question

[Koen]

I have this Map

private Map<Class<? extends IBusinessRule>, Collection<? extends
IBusinessRule>> businessRules;

where IBusinessRule is an interface, but what I actually want is
something like this

private <T extends IBusinessRule> Map<Class<T>, Collection<T>>
businessRules;

This is a map from the Class of an object to a Collection of objects
with exactly that type.

Is this possible? I can not figure out how to do that.

Koen

 

[Ingo R. Homann]

Hi,

I have this Map

private Map<Class<? extends IBusinessRule>, Collection<? extends
IBusinessRule>> businessRules;

where IBusinessRule is an interface, but what I actually want is
something like this

private <T extends IBusinessRule> Map<Class<T>, Collection<T>>
businessRules;

This is a map from the Class of an object to a Collection of objects
with exactly that type.

Is this possible?

Yes, it is. But T has to be defined in the class or method:

class X<T extends IBusinessRule> {
private Map<Class<T>, Collection<T>> businessRules;
}

or

class X {
public <T extends IBusinessRule> void foo(Map<Class<T>,
Collection<T>> businessRules) {
...
}
}

Hth,
Ingo

 

[Koen]

Ok, I understand, but I forgot to mention that this map businessRules is
a static field...

Koen

 

[Ingo R. Homann]

Hi,

Ok, I understand, but I forgot to mention that this map businessRules is
a static field...

Then, it is impossible. If it where possible - how/where would you like
to define it? (The fact that you cannot answer this question is the
reason why it is impossible!

Ciao,
Ingo