inzaghi
asked on
method execution on interfaces using reflection
I have a property defined which is a comma seperated list of classes.
Each one of these classes extend a Class A and implement methods of class B.
What I want to do is for each class in this list is to use the Class.forName(className) and
create a instance of this class using class.newInstance().
I know how to do this.
But how would I invoke the methods on class A and Class B. Would I need to cast the object returned from class.newInstance() to A then invoke its method and then cast to the interface B and invoke its method
ie Object o = class.newInstance();
A objectA = (A) o;
objectA.doIt();
B interfaceB = (B) o;
interfaceB.method1();
interfaceB.method2();
Each one of these classes extend a Class A and implement methods of class B.
What I want to do is for each class in this list is to use the Class.forName(className) and
create a instance of this class using class.newInstance().
I know how to do this.
But how would I invoke the methods on class A and Class B. Would I need to cast the object returned from class.newInstance() to A then invoke its method and then cast to the interface B and invoke its method
ie Object o = class.newInstance();
A objectA = (A) o;
objectA.doIt();
B interfaceB = (B) o;
interfaceB.method1();
interfaceB.method2();
No - no need to cast to B
> no need to cast to B
yes you would to access the B methods
yes you would to access the B methods
>>yes you would to access the B methods
No - you shouldn't need to if A implements B
No - you shouldn't need to if A implements B
ASKER
Class A does not implement B,
public class C extends A implements B{
}
public class C extends A implements B{
}
Now you're confusing me - C wasn't mentioned before ;-) In that case you don't need to cast C to B
ASKER
Sorry for the confusion, just for clarity c is a actual class name that is defined in the comma seperated list of class names
Question seemed quite clear to me :)
ASKER
To invoke the individual methods on the class A and B is it better to cast first or use reflection to get the methods and invoke?
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ASKER
I will be creating Objects of the class C using:
Object object = Class.forName(className).n
Now how can I cast this object to its orginal type ie class C, would this do it
C objectC = (className.class) Class.forName(className).n
Object object = Class.forName(className).n
Now how can I cast this object to its orginal type ie class C, would this do it
C objectC = (className.class) Class.forName(className).n
Cast as you would normally:
C c = (C)Class.forName(className
C c = (C)Class.forName(className
You have a choice:
a. casting as above
b. using reflection to invoke the methods you want to invoke on the Object reference
a. casting as above
b. using reflection to invoke the methods you want to invoke on the Object reference
SOLUTION
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SOLUTION
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:-)
or you can use reflection to get the Method instance and exeute it.