Method.invoke causes IllegalArgumentException with subclass instance

Question

Is there a way to use an instance of a subclass when using reflection to invoke a method?
Given the following code, I want to be able to use reflection to invoke the "doSomething" method within the Foo class. However, I want to use an instance of Bar as the parameter value when using reflection (since an instance of Bar is implicitly an instance of Foo; I have also tried casting the Bar instance, b, to Foo but this does not work). Doing this yields an IllegalArgumentException.
What am I missing? What am I doing wrong? What do I have to do in order to use an instance of Bar with "invoke"?
// Foo.java
package junk;
public class Foo
    private void doSomething(Foo f)
        System.out.println("Doing something with a " + f.getClass().getName());
    public static void main(String[] args)
        Foo f = new Foo();
        Bar b = new Bar();
        f.doSomething(f);   // Outputs "Doing something with a junk.Foo"
        f.doSomething(b);   // Outputs "Doing something with a junk.Bar"
        Class[] paramTypes = new Class[] { f.getClass() };
        Object[] paramValues = new Object[] { b };
        b.invokePrivateFooMethod("doSomething", paramTypes, paramValues); // Doesn't work
// Bar.java
package junk;
import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;
public class Bar extends Foo
    public void invokePrivateFooMethod(String methodName,
                                       Class[] paramTypes,
                                       Object[] paramValues)
        try
            Foo localF = new Foo();
            Class classToUse  = localF.getClass();
            Method methodToUse = classToUse.getDeclaredMethod(methodName, paramTypes);
            methodToUse.setAccessible(true);    // override of private modifier
            methodToUse.invoke(classToUse, paramValues);
        catch (IllegalAccessException e)
            e.printStackTrace();
        catch (NoSuchMethodException e)
            e.printStackTrace();
        catch (InvocationTargetException e)
            e.printStackTrace();
}

Answer 1

Sorrry for the confusion. It's always the little things...
I neglected to use an instance of Foo to invoke the method.
See corrected code below:
// Bar.java
package junk;
import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;
public class Bar extends Foo
    public void invokePrivateFooMethod(String methodName,
                                       Class[] paramTypes,
                                       Object[] paramValues)
        try
            Foo localF = new Foo();
            Class classToUse  = localF.getClass();
            Method methodToUse = classToUse.getDeclaredMethod(methodName, paramTypes);
            methodToUse.setAccessible(true);    // override of private modifier
            // NOTE:  Use localF, NOT classToUse!
            methodToUse.invoke(localF, paramValues);
        catch (IllegalAccessException e)
            e.printStackTrace();
        catch (NoSuchMethodException e)
            e.printStackTrace();
        catch (InvocationTargetException e)
            e.printStackTrace();
}