sample code to invoke ReflectionMethodInvoker of groovy

reflectionInvoker.groovy

import org.codehaus.groovy.runtime.ReflectionMethodInvoker

class Base{}
class Derived extends Base{}
class Derived2 extends Derived{}
class Hello{
  public void hello(Base b){
     println "base"
   }
   public void hello(Derived d){
     println "derived";
   }
 }

h = new Hello()
ReflectionMethodInvoker.invoke(h, "hello", new Base())
ReflectionMethodInvoker.invoke(h, "hello", new Derived())
ReflectionMethodInvoker.invoke(h, "hello", new Derived2())

result.txt

base
derived
derived