public   interface  Facade
{
    @Action("DoA")
     public   Float  doA( int  i);
    @Action("DoB")
     public   Float  doB( Double  d);
}



@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
 public  @ interface  Action
{
    String value();
}


 public   class  Invoker
{
     static   final  Map<String, Method> map =  new  HashMap<String, Method>();
     static 
    {
        Method[] declaredMethods = Facade. class .getDeclaredMethods();
         for  (Method method : declaredMethods)
        {
            Action action = method.getAnnotation(Action. class );
            map.put(action.value(), method);
        }
    }
    Object invoke(String action, Object target, Object... args)  throws  IllegalAccessException, InvocationTargetException
    {
         return  map.get(action).invoke(target, args);
    }
}