How do I return a defined Map?

I want to define a function which returns an instantiated map depending on the Key and Value class which I give it:

something like

Map<Integer, String> map = getMap(Integer.class, String.class);

but I am unsure how to define the getMap function in the correct way. I was thinking something like

<K,V> Map<K,V> getMap(Class<K> keyClass, Class<V> valClass) {
   Map<keyClass, valClass> retMap = new HashMap<keyClass, valClass);


   .... // add values to my map

   return retMap;
}

But this doesn't seem to work at all.

does anyone have any suggestions?