http://gis.pku.edu.cn 1 － 50 web service and geographical information integration —— peking...

http://gis.pku.edu.cn

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Web Service and Geographical Web Service and Geographical Information IntegrationInformation Integration

—— —— Peking Peking Spatial Applications Integrating Infrastructure, Spatial Applications Integrating Infrastructure, A Research for Spatiality-oriented Web Service ApplicationA Research for Spatiality-oriented Web Service Application

Lab of Spatial Information System@PKULab of Spatial Information System@PKU


[email protected]


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Syllabus Syllabus

• Introduction of Spatial ApplicationIntroduction of Spatial Application

• Design Intention of Peking Spatial Applications Design Intention of Peking Spatial Applications Integrating Infrastructure(PAI)Integrating Infrastructure(PAI)

• Web Service-Based Distributed Spatial Web Service-Based Distributed Spatial Information Disposition ArchitectureInformation Disposition Architecture

• QoS Strategies in Spatial Information Integration QoS Strategies in Spatial Information Integration & Disposition& Disposition

• An Example for PAI-Organized ApplicationsAn Example for PAI-Organized Applications


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Introduction of Spatial ApplicationIntroduction of Spatial Application

• Characteristic of Spatial Information and Manipulation Characteristic of Spatial Information and Manipulation PlatformPlatform Spatial information:

Massive; Long time of data sedimentation; Multiple spatial data models; Adhere to certain GIS platform to be accessible; …

Spatial information manipulation platform: Data stored in heterogeneous GIS(dominated as

MapInfo, ArcInfo) platform or inner spatial module presented by certain manufacturers(Oracle Spatial by Oracle);

Relevant services, product series based on platform self-defined organization;

Single accessible data portal; …


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• Characteristic of Conventional Spatiality-oriented Characteristic of Conventional Spatiality-oriented ApplicationApplication Direct development of application based on platform-Direct development of application based on platform-

critical architecture;critical architecture; Spatial information visualization, query, and edition Spatial information visualization, query, and edition

at the front end based on homogeneous data storage at at the front end based on homogeneous data storage at the back end;the back end;

Whenever inter-platform integration is needed, the Whenever inter-platform integration is needed, the writing of application-related adapter software for writing of application-related adapter software for each participating platform is used;each participating platform is used;

…… ……


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• Challenges imposed by nowadays spatial data Challenges imposed by nowadays spatial data integration:integration: Participated by processes running on heterogeneous Participated by processes running on heterogeneous

platforms from multiple organizations;platforms from multiple organizations; Integrating existed spatial application systemsIntegrating existed spatial application systems;; Implement of dynamic integrationImplement of dynamic integration accounting for on- accounting for on-

time subsystem scalability;time subsystem scalability; Refining of existing services to present QoS Refining of existing services to present QoS

attributes during integrated service formation;attributes during integrated service formation; Semantic level interoperation to obtain automatic Semantic level interoperation to obtain automatic

service communication and assemblage;service communication and assemblage; …… ……


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• Which we are confronted lies in that:Which we are confronted lies in that:

Prevalent large-scaled spatial applications(Digital Prevalent large-scaled spatial applications(Digital City, ECity, E-Government-Government) call for a more ) call for a more flexible, flexible, dynamical, semanticdynamical, semantic integration among existing integration among existing legacy data, system, platform and framework. legacy data, system, platform and framework.


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• Work of OGC in Improvement of Spatial Interoperability A common architectural framework for web-based

geospatial services; Concentrating on definition of behavior of functional

components common to all such services and extensible for specific services and service types;

Specification for distributed computing interaction, distributed computing workflow

• Our Emphasis: Above-base integration of Web Services to obtain dynamic interoperation


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• Design Intention of Peking Spatial Applications Design Intention of Peking Spatial Applications Integrating Infrastructure(PAI) Integrating Infrastructure(PAI)




Syllabus Syllabus


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Design Intention of PAIDesign Intention of PAI

• The main goal of PAI infrastructure is to provide open

second-time developing platform of spatial information

application integration;

• Provide united sharing mechanism and support

technologies to access and acquire spatial information;

• Solve distributing and heterogeneity of spatial

applications(such as heterogeneity of GIS platforms,

systems, expression and semantic collision);

• Provide interoperation platform for isolated spatial

applications


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Design Intention of PAIDesign Intention of PAI

• Reasons for the construction of PAI based on Reasons for the construction of PAI based on Web Service oriented distributed frameworkWeb Service oriented distributed framework Web Service concentrates on fast conformity and Web Service concentrates on fast conformity and

deployment of legacy systems, which facilitates the deployment of legacy systems, which facilitates the integration of existing spatial applications;integration of existing spatial applications;

Web service can separate system implementation and Web service can separate system implementation and function interfaces by function publishing as services, function interfaces by function publishing as services, which permits flexible function replacement in which permits flexible function replacement in implementation aspect;implementation aspect;

Security of sensible data and relevant services inside Security of sensible data and relevant services inside some industries are well protected because of the some industries are well protected because of the separation between interfaces and implementationsseparation between interfaces and implementations


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Syllabus Syllabus


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Web Service-Based Distributed Spatial Web Service-Based Distributed Spatial Information disposition ArchitectureInformation disposition Architecture


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Syllabus Syllabus


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QoS Strategies in Spatial Information QoS Strategies in Spatial Information Integration & DispositionIntegration & Disposition

• Problems deserved consideration in current Problems deserved consideration in current integration:integration: Massive spatial information presented in GML

format in PAI to ease interaction, while GML is pain-text format, which leads to deficiency in transmission;

Frequent map retrieval which calls for data caches to be maintained both in Adapter Service or in Integrating Coordinator(IC) Layer;

Differentiated Services of map to the clients which have different network situations and application requirements;

……


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• Current QoS Strategies in PAICurrent QoS Strategies in PAI

GML data compressionGML data compression

During data transformation & client-end transmission;

Compression editions maintained in caches of IC Layer

Implementation of cache mechanism flexible to multiple Implementation of cache mechanism flexible to multiple

spatial data granularitiesspatial data granularities

Caches by Adapter Service, IC Layer & Web browsers

Elaborate selection of content-equivalent data providersElaborate selection of content-equivalent data providers

Non-function facets, history records & fatal parameters of Web

services

Other QoS-related Differentiated ServicesOther QoS-related Differentiated Services

Vector map clipping, On-line map generation …


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A typical application aided by QoS strategy based on PAI architecture

Geo-UnionDatabase

ArcInfoMap File

MapInfoMap File

Applet

Metadata Requesting

User Requesting

PAIToolkits

MDS

QueryingWebService

Services Requesting

Coordinate Transformer Spatial Analysisor

WebApplication

Using

QoS Interaction Process

Considering


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• Typical Workflows:Typical Workflows:

Sample API in PAI Sample API in PAI ToolkitsToolkits

Invoked Web Service WorkflowInvoked Web Service Workflow

retrieveMapretrieveMap

(MapName)(MapName)

MDS(for layer info & adapter service Info)MDS(for layer info & adapter service Info)

Adapter Service(for corresponding GML data Adapter Service(for corresponding GML data of certain layer)of certain layer)

retrieveMapasJPEGretrieveMapasJPEG

(MapName)(MapName)

QoS Consultation Service(for Cache Info) QoS Consultation Service(for Cache Info) (Uncached) MDS (Uncached) MDS Adapter Service Adapter Service

(Cached)(Cached)

Spatial Analysis Service(for on-line JPEG Spatial Analysis Service(for on-line JPEG transformation)transformation)


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Syllabus Syllabus


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Examples for PAI-Organized ApplicationsExamples for PAI-Organized Applications

• We have implemented the LBS service based on We have implemented the LBS service based on PAI framework PAI framework

• Designed for both mobile terminal and PCDesigned for both mobile terminal and PC

• Provides some location-based services Provides some location-based services

finding the nearest service facilities (for example banks)finding the nearest service facilities (for example banks) getting the nearest services facilitiesgetting the nearest services facilities finding the position of oneself or one’s friendsfinding the position of oneself or one’s friends getting the relevant information about appointed getting the relevant information about appointed

position position …………


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Examples for PAI-Organized ApplicationsExamples for PAI-Organized Applications


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Components of Layers in LBS

Web Client

Web Application

Integrated Coordinator

Distributed

Services

Distributed Information

PC 、 Mobile phone 、 multimedia message 、 laptop and so on

LBS Server

LBS Worker GML Retriever

Metadata services, Spatial data gateway, GML analyzing services, Format adapt Services

Metadata database, Spatial data file, Database and map layer file on Oracle Spatial, Geo-Union, MapInfo

An Example for PAI-Organized ApplicationsAn Example for PAI-Organized Applications


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An Example for PAI-Organized ApplicationsAn Example for PAI-Organized Applications


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Another Work in Our LabAnother Work in Our Lab

GMLWeb Resource

GMLWeb Service

GMLApp Service

PKGML Kernel

DataAccessing

DataParsing

Cachingand

Indexing

MemoryData

Pooling

Displayingand

Interacting DataStructure

andAlgorithms

PKGMLApplet

PKGMLPortable

PKGMLComponent

A GML-bases lightweight WebGIS system PKGMLhttp://m

ap.pku.edu.cn


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Lab of Spatial Information System@PKULab of Spatial Information System@PKU


[email protected]

http://gis.pku.edu.cn 1 － 50 web service and geographical information integration —— peking...

Documents

spatial data integration

inner spatial module

interplatform integration

writing of application

participating platform

arcinfo platform

certain gis platform

dynamic integration