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OrbisWPS : Open-source Web Processing Service (WPS) libraries. Build Status

OrbisWPS contains a set of OSGI libraries to build a Web Processing Service (WPS) compliant with the 2.0 specification. OrbisWPS is developed by the GIS team of the Lab-STICC laboratory, located in Vannes. It has been supported by research projects:

  • MapUCE (Modeling and urbAn Planning laws: Urban Climate and Energy, 2014-2018), ANR Programme: Villes et Bâtiments Durables (VBD) 2013

  • ENERGIC-OD Project (European Network for Redistributing Geospatial Information to user Communities - Open Data; 2014-2017) partially funded under the ICT Policy Support Programme (ICT PSP) as part of the Competitiveness and Innovation Framework Programme by the European Community and the French geographic portal GEOPAL of the Pays de la Loire region.

  • PAENDORA (Planification, Adaptation et Energie des DOnnées territoriales et Accompagnement, 2017-2020), ADEME Programme: MODEVAL-URBA 2017

  • URCLIM (URban CLIMate services, 2017-2020), JPI Climate Programme

As part of the OrbisGIS platform, OrbisWPS is funded and maintained by personal resources of the Lab-STICC GIS team.

Groovy API

API for the Groovy language to write WPS scripts. This module contains the declaration of annotations based on the WPS 2.0 standard. The script writing is done in two parts : the input/output declarations and the process itself.

The input and output declaration is done by annotated all the variable with @...Input or @...Output, with ... replaced by the data type. As example :

@EnumerationInput( title = "title", values = ["round", "flat", "butt", "square"])
String[] enumeration

@LiteralDataInput(title = "title)
String string

@LiteralDataOutput(title = "title)
Long number

The available data type are :

  • LiteralData : String and Number like int, long, short ...
  • BoundingBox : String representation of a bounding box with the pattern : authority:code, like EPSG:2000.
  • ComplexData extensions :
    • Enumeration : String array representation of a selection of values from a predefined list.
    • Geometry : String representation of a geometry in WKT.
    • JDBCTable : String representation of a JDBC table.
    • JDBCColumn : String representation of a column of a JDBC table.
    • JDBCValue : String representation of a value of a column of a JDBC table.
    • Password : String representation of secret String.
    • RawData : String representation of a file or forlder, not atter its extension.

The process itself is written inside a method called processing() (the name can't be changed) annotated @Process.

Scripts

This module contains basic WPS scripts and are loaded in the WPS server by the class WpsScriptPlugin thanks to the OSGI mechanism.

Server module

This module contains the whole WPS mechanism which can be divided into two part : the script parsing and the WPS request execution. The WPS service can be customized by instantiating the WpsServerImpl class with a customized version of the properties file

Script parsing

The script parsing is done in 3 steps :

  • The script parsing is based on the Groovy parser which convert the groovy files into java classes.
  • Then those classes are inspected to search for the groovy annotations defined in the Groovy-API module and to generate the JAVA object representation of the process. A part of the model comes from the JAXB generated classes from the ogc-custom-jaxb library and the model package of the module (package containing the custom extension of the ComplexDataType class).
  • To finish the Java object are stored into a cache list and becomes available throw the service.

WPS request execution

The process execution is done by the WpsServerImpl.callOperation() method which receive an InputStream object containing the WPS 2.0 request.

The request is then parsed and executed. In the case of the Execute request, an instance of the java class of the desired script is instantiated and configured with the input. Then the method processing() is executed. Once the execution end reached, the output data a retrieved.

Client

API interface and classes for the creation of a WPS client compatible with the server.