How can i cast a response object to a vector object?? if this is not possible what shud i do?
A "response object" doesn't mean anything specific, but you almost certainly can't cast anything to a vector.
By response object I'm going to assume you mean the return value from a method--if that's the case, you need to know just what type the method returns.
If your response is an array, I believe there may be a new ArrayList(someArray) constructor. (An ArrayList is basically a vector).
If your "response object" is a String, an int, or an Object of some other scalar quantity, you will probably have to create the ArrayList/Vector yourself and add it.
If you are looping and getting responses from each call to a method, then you probably want to instantiate the ArrayList before you start the loop, then add to it on each iteration.
I'm sure there are many cases I missed, if you could be more specific, we could be more helpful.