Database Server Models for WMS and WFS Geographic Web Services - Geographical Information Systems: Trends and Technologies - page 168

Easily integrated in the Java Eclipse platform, Geotools is the basic
component of some GIS tools (i.e., UDig). Its modular architecture and
its use to develop Geoserver, leads us to use it as a basic component for
cartographic applications.
From the database server side, interfaces to model RL have been
realized. From the application server, using a database schema provided
by a distant server, an application has been developed to enhance attribute
information and to display them. A presentation of these interactions is
available in (El Ghouasli et al. 2012).
Figure 11 presents the specifi c application interactions. An application
interacts with a middleware. The fi rst step is the connexion that will provide
the Instantiated Lattice of Concepts (ICL) from the server side using WFS
services. The second step is a dynamic step that adapts the received ICL to
users' needs. The Operational Lattice of Concepts (OLC) is now available.
Since this step is dynamic, it can be performed several times within the
same working session. The third step is an access demand. Using the RL, the
received (G/X)ML fi les from WMS/WFS services are extended or reduced
depending on users' needs. The application handles these (G/X)ML fi les
as if they were original ones provided by WMS/WFS calls.
The lattice of concepts is shared by the different applications. The
Operational Lattice is specific to each database server depending on
available data. The modeling of each lattice is similar since they cover the
same modeling (here an acyclic graph). A conventional database can take
charge of this modeling.

CLIENT

SERVER

Application

n Connection
o Complexity
requirements
p Access
WMS/WFS

Public
Specification
Interface

Database

Middleware

n WFS ICL

p {WMS/WFS}

o OCL

OLC

Fig. 11. Specifi c applications interactions.