3.2 AO Class

A specific class hierarchy must be created in order to accommodate the host.domain information which can be used to classify the AO at coarse level. The top of this hierarchy is a class named URL which must have (at least) the following attributes:

Domain_0 (e.g www,gopher,ftp,s700)
Domain_1 (e.g. ncsa,telepac,inescn,di)
Domain_2 (e.g. uiuc,inesc,uminho)
... (...)
Domain_n (e.g. com,pt,org,edu)

At the same time, URL's subclasses reflect the possible scheme values and even filename extensions. However, if for a given URL the value scheme + filename extension is not the name of an existent (pre-defined) class then only the scheme value is used. The following class hierarchy is a tentative illustration of this idea and specifies some possible subclasses for the HTTP class:

URL
FILE
HTTP
HTTPHTML (Html documents)
HTTPTXT (Text documents)
HTTPPS (Postscript documents)
HTTPDOC (Word documents)
HTTPTEX (TeX documents)
HTTPGIF (Gif images)
HTTPZIP (Zipped files)
GOPHER ...
...
WAIS ...
...
NEWS ...
...
TELNET ...
...

Of course, other attributes may be added to the classes reflecting the specific information of their objects.


F. Luís Neves and José N. Oliveira , "Classifying Internet Objects" in WWW National Conference'95, Minho University, Braga, Portugal