Abstract: A data processing method for use with a plurality of exception processing environments executes an application program on which an object to be supplied with an error message upon occurrence of an exception event which is likely to cause interruption of the normal execution of the application program is previously registered. If an exception event occurs occurred, an exception occurrence message indicating occurrence of the exception event is sent to a pre-set object. The pre-set object supplied with the exception occurrence message, generates an error message corresponding to the exception event indicated by the exception occurrence message and sends the generated error message to the registered object. The registered object sends a message commanding execution of a pre-set process corresponding to the error message to the application program associated with the exception event.