Currently, the only subclass of HyperLink is UrlLink. UrlLink contains a Url and a Request object. Url is the UID used in the web. Request is a Command object [GOF] that contains all the information needed by the Protocol to access a HyperComponent. The Url and Request is assigned by UrlResolver.
Note that the current definition of HyperLink is not the same as the one in the Dexter Model. The Dexter Model defines the content of link components as a collection of two or more link specifiers. Each link specifier specifies an end point of a hypertext link. For a two-way link, there are two specifiers. For a three-way link, there are three specifiers... and so on. The details of link specifier are explained in the section Common abstractions of hypertext systems ,[first dexter], and [second dexter].
If HyperLink follows the Dexter Mode, then it would look like Figure 1 when a link is retrieved by LinkResolvers.
Figure1. HyperLink that follows the Dexter Model.