Java APIs

I'm looking for a way, or a correct syntax, for 'genericizing' the
class instantiation via Class#newInstance() method using reflection.
The code shown below is an half-baked solution in that compiler emits
unchecked cast warning against the cast on the 'obj' variable at the
last part of the code.

I think I have tried everyting conceivable for Class variable declarations
and other part of the code but they were all futile. I lost one night
sleep for that.

If there are Java Generics gurus on the forum, please help!

TIA.

import java.util.*;
import java.lang.reflect.*;

public class GetMethod{
  public static void main(String[] args) {
    Object obj = null;
    Class<Hashtable> clazz = Hashtable.class;
    Class<Class> claxx = Class.class;
    try {
      Method method = claxx.getMethod("newInstance");
      obj = method.invoke(clazz);
    } 
    catch (Exception e) {
      e.printStackTrace();
    }
    Hashtable<String,String> ht = (Hashtable<String,String>)obj;
    ht.put("foo", "bar");
    System.out.println(ht.get("foo"));
  }
}