Invalid cast type error

[Glenn Robinson]

Glenn Robinson <[email protected]> scribbled the following

Michael Borgwardt wrote:

Glenn Robinson wrote:
I create a new class object at runtime using:

Class dmClass = Class.forName(dmClassName);
[]
How can I use dmClass as the cast type in a statement?

You cannot, that's impossible.

What are you trying to achieve with it anyway?

I have:
interface DataManager
class SasDMImp which implements DataManager

I do the following:

String dmClassName = "SasDMImp";
Class dmClass = Class.forName(dmClassName);

I now want to use the SasDMImp class to cast a new object and this is the
part I'm having trouble with.

If I hard code the class name I use:

SasDMImp dm = (SasDMImp) Naming.lookup("rmi://" +host + registry);

I want to replace the hard coded SasDMImp with dmClass but I get the
Invalid Cast type when I do this.

Hope this helps.

This is a well-known situation. Our application uses this form of code
about a hundred times.
My answer to your problem is: Forget about casting to SasDMImp. Cast to
DataManager instead, as it's a known interface, and code that uses your
data manager shouldn't have to care about whether you have a SadDMImp or
some other implementation. If it does, you have a design problem.

Thanks, this is what I wanted. I cast using the interface DataManager and
all worked just fine.

Appreciate you comments and help.

Glenn