code: public static BeanInfo getBeanInfo(Class<?> beanClass, Class<?> stopClass)
              throws IntrospectionException {
          if(stopClass == null){
              //try to use cache
              return getBeanInfo(beanClass);
          }
          return getBeanInfoImplAndInit(beanClass, stopClass, USE_ALL_BEANINFO);
      }
docs: Gets the <code>BeanInfo</code> object which contains the information of
  the properties, events and methods of the specified bean class. It will
  not introspect the "stopclass" and its super class.
  
  <p>
  The <code>Introspector</code> will cache the <code>BeanInfo</code>
  object. Subsequent calls to this method will be answered with the cached
  data.
  </p>
  
  @param beanClass
  the specified beanClass.
  @param stopClass
  the sopt class which should be super class of the bean class.
  May be null.
  @return the <code>BeanInfo</code> of the bean class.
  @throws IntrospectionException