52°North Web Processing Service

The 52°North Web Processing Service (WPS) enables the deployment of geo-processes on the web in a standardized way. It features a pluggable architecture for processes and data encodings. The implementation is based on the current OpenGIS specification: 05-007r7.

Its focus was the creation of an extensible framework to provide algorithms for generalization on the web.

More information available at the 52°North Geoprocessing Community.

Features

• Java-based Open Source implementation.
• Supports all features and operations of WPS specification version 1.0.0 (document 05-007r7)
• Pluggable framework for algorithms and XML data handling and processing frameworks
• Build up on robust libraries (JTS, geotools, XMLBeans, servlet API, derby)
• Experimental transactional profile (WPS-T)
• Web GUI to maintain the service

Supported Backends

The 52°North WPS provides wrappers to well-established (geographical) computation backends.

• WPS4R - R Backend
• GRASS out of the box extension
• 220+ SEXTANTE Processes
• ArcGIS Server Connector
• Moving Code backend, including Python support

Development

Use git to clone the WPS repository:

git clone https://github.com/52North/WPS.git

Then just run mvn clean install on the repositories root directory.

GeoTools

Due to licensing issues all GeoTools based input/output handlers and algorithms are not included by default. If you want to use them (or any backend relying on them), you have to explicitly enable them with the with-geotools profile:

$ mvn clean install -P with-geotools

To run your project in Eclipse with geotools support using the WTP plug-in (52n-wps-webapp -> Run As -> Run on Server) add the profile to the Active Maven profiles in the project properties of 52n-wps-webapp (right click on the project, select "Maven", add with-geotools to the text field).

Non-default configuration file

There are several ways to supply a wps_config.xml file:

Configure at build time

With a path:

The supplied path will be written to the web.xml and will be used at runtime. For this to work, the path should be absolute.

$ mvn install -Dwps.config.file=/path/to/external/file/that/will/be/used

With a file:

The supplied file will be copied to the WAR file and will be used at runtime.

$ mvn install -Dinclude.wps.config.file=/path/to/external/file/that/will/be/copied

Configure at runtime

With a system property

The supplied value will override every other configuration.

$ java [...] -Dwps.config.file=/path/to/external/file/that/will/be/used

This works well with a server configuration in Eclipse WTP. Open the server editor, click "Open launch configuration" and add the property to the VM arguments.

Using JNDI:

The supplied value will override every other configuration except a possible system property. See the [Apache Tomcat documentation](https://tomcat.apache.org/tomcat-7.0-doc/config/context.html#Environment Entries):

<Context ...>
  ...
  <Environment name="wps.config.file"  value="/path/to/file"
               type="java.lang.String" override="false"/>
  ...
</Context>

Using the servlet config

You can edit the web.xml after creation and substitute another path:

<servlet>
    <servlet-name>WPS</servlet-name>
    <servlet-class>org.n52.wps.server.WebProcessingService</servlet-class>
    <init-param>
        <param-name>wps.config.file</param-name>
        <param-value>/path/to/file</param-value>
    </init-param>
</servlet>

Using the user home directory

Create a file named wps_config.xml in the home directory of the user that executes the servlet container.

Integration Testing

The WPS comes with a variety of integration tests which are performed using Jetty. In order to execute integration tests in a maven build, activate the dedicated profile through mvn clean install -Pwith-geotools,integration-test.

Contributing

You can find information about how to contribute to this project in the Geoprocessing Wiki.

License

This project consists of modules which are published under different licenses.

• API: The internal API is published under The Apache Software License, Version 2.0. If you want to build your own algorithms you can depend on these modules alone and release it under any compatible open source license. The API consists of the following modules:
  • 52n-wps-algorithm
  • 52n-wps-commons
  • 52n-wps-io
• Web service: The implementation of the internal API allows to publish algorithms online as a web service. The web service implementation is published under the GNU General Public License Version 2. The following modules make up the web service implementation:
  • 52n-wps-ags
  • 52n-wps-algorithm-geotools (with exceptions to EPL libraries)
  • 52n-wps-algorithm-impl
  • 52n-wps-client-lib
  • 52n-wps-database
  • 52n-wps-grass
  • 52n-wps-io-geotools (with exceptions to EPL libraries)
  • 52n-wps-io-impl
  • 52n-wps-mc
  • 52n-wps-python
  • 52n-wps-r
  • 52n-wps-server
  • 52n-wps-server-soap
  • 52n-wps-sextante
  • 52n-wps-transactional
  • 52n-wps-webadmin
  • 52n-wps-webapp

For details see the LICENSE and NOTICE files. Be aware that some modules contain their own LICENSE and NOTICE files.