Transcript Web Mapping Interoperability in Practice

Web mapping interoperability in practice, a Java
approach guided by the OpenGis Web Map
Server Interface Specification
Pedro Fernández, R. Béjar, M.A. Latre, J. Valiño, J.A. Bañares, P.R. Muro-Medrano
EC-GIS 2000,
28-30 June, Lyon, France
Computer Science and System Engineering
Department
C.P.S. University of Zaragoza, Spain
Copyright © 2000 Pedro Fernández Bel
Index
1) Introduction
2) The Web Map Server Interface
Specification
3) A Java approach
3.1)
3.2)
3.3)
3.4)
Java GIS engine
Web Map Server Architecture
Configuration Tools
Map Clients
4) Conclusions
Introduction
OpenGIS
Interoperability
GIS
Web Map Server
Java
Internet
Web Map Server Interface


The Web Map Server Interface Specification is a
set of service descriptions to serve maps on
Internet
Objectives
Publish maps on Internet
 Interoperability


Viewer
Client
Service
Registry
Services
Map
 Capabilities
 Feature Info

Map
Server
Map
FeatureInfo
Capabilities
WMS interface: Map Request


The main service: Produce a map
Parameters
zone
 reference system
 content of the map (layer & styles)
 format


Render suitable to client displaying capabilities
pictures (JPEG, GIF, PNG)
 series of graphical elements (SVG)
 packaged geographic data (GML)

Java approach to the WMS

We develop ‘small’ Geographic Information Systems
Distributed
 Integration of geographic information


Java
Multiplatform
 Net management capabilities


Java GIS engine
GIS support for our systems
 Web map server integrates the GIS engine.
 Used in two Java clients of the WMS
 Used in other projects: Fleet Tracking Systems or Mining

GIS engine

The application GIS capabilities are supported by
our own GIS engine
Reusable Java Component
 GUI for final applications
 Map Support



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

Zoom, Pan, Selections
Layer management capabilities
Vector and raster data supported
Multi-render for vector data
Access to remote data
GIS Tools
Map Control
GIS engine
component
Raster
Vector
WMS architecture
Web Map Server
<<HTTP resquest>>
OpenGIS
WMS
interface
JMapServer
HTTP
Parser
Servlet
<<RMI>>
Map Request Builder
<<HTTP response>>
Temporal
Map
Images
Capabilities
generator
Capabilities
Manager
Capabilities
XML
GIS
Visualization
Map data
Vector +
Images
Map
generator
JMapServer




Implements Web Map Server Interface
Specification v0.9
Java 100%
Free of external licenses 100%
Accesible through an RMI interface
HTTP Servlet translates HTTP requests
 Integration with other Java application
 JMapServer can be remote
 Dynamic updating of data


Fleet Tracking Systems
Configuration tools


Facilitates management of the Web Map Server
Map Generator
Graphic tool to generate maps
 Based on the previous GIS engine
 Build maps using data+render in a propietary format


Capabilities generator
Graphic tool to manage XML capabilities file
 Configure all the parameters of the map server

WMS Clients

Three kind of clients

Functionality easily extendable

GIS capabilities can be integrated in more
complex visualisation clients
Fleet Tracking Systems
 Mining

WMS Client architecture
Client side
Server side
OpenGIS
WebMapServer
Thick Thin(downloaded)
<<Java 2 >>
Java client
JMapServer
Local
data
<< HTML >>
HTML client
JMapServer
Web Server
<<Java 2 >>
Applet client
WMS Client example: HTML page
WMS Client example: Java2 Applet
Java2 Visualisation application
Conclusions (1)

Web Map Server
Version 0.9 implemented.
 Interoperability among map repositories
 Can be integrated into bigger geographic information
systems


Java
Esential for the development of the application
 Allows building portable software.
 Solves net requirements

Conclusions (2)

Clients
Allow different levels of interaction with server.
 Provide an extensible set of functionalities


GIS-engine
Reusable Java component
 Used to build the web map server, and the clients
 Reused in other GIS systems (mining, fleet tracking
systems)

Contact

email: [email protected]
http://iaaa.cps.unizar.es
Thank you for your attention!!