A Service Oriented Architecture (SOA) promises to make integration of
heterogeneous systems easy or at least possible.
By building (standardized) services on top of existing components, existing systems
do not become deprecated, instead they will become better accessible. Web services
are the building blocks for the implementation of business processes in a web-based
SOA. But how can these business processes be described and executed without loosing
flexibility? And how do geospatial web services fit in here?
BPEL (Business Process Execution Language) is often mentioned as the
preferred standard to implement business processes in Service Oriented
Architectures. Using BPEL one can describe its business processes in a
standardized way and should be able to execute them with any BPEL engine of
choice. Since BPEL is originally designed for web services (with the W3C
standards WSDL and SOAP in mind), the question arises whether it can be
used on geospatial web services as well, hereby enabling integration of
these web services with common web services.
Geodan (a Dutch GIS company) has performed practical research to find out
to what extent BPEL is suitable to use on OGC compliant web services like WFS
and WMS. A mixture of open source and proprietary products has been used in
this research. These products include Postgres/Postgis, Geoserver, Axis and
Oracle's BPEL Process Manager. BPEL, the web services used, the necessary
modifications and results of the research will be discussed in the
presentation. |