Java generic function: how to return Generic type

Question

Here\'s a Java generic pattern:

public  T getResultData(Class resultClass, other_args) { 
   ...
   return resultClass.cast(T-thing);
}
         


        

Answer 1

Well,. here's an ugly (partial) solution. You can't generically paramaterize a generic param, so you can't write

public > T getResultData ...

but you can return a parameterized collection, e.g. for a set

public < T extends Set< U >, U > T getResultData( Class< T > resultClass, Class< U > paramClass ) throws IllegalAccessException, InstantiationException {
        return resultClass.newInstance();
    }

where you could get rid of the U-param if it existed in the class signature.