Internals

The following material has been prepared by Justin Deolivera documenting the GTXML framework:

• Overview
• Bindings
• Configuration
• Code Generation
• Purchase Order Tutorial

Generated objects matching the xml schema:

• net.opengis.ows : open web services schema
• net.opengis.wfs : web feature service
• net.opengis.wps : web processing service schema
• net.opengis.wcs : web coverage service schema
• net.opengis.wfsv : web feature service schema
• org.w3.xlink : xlink schema

Schema and bindings plugins:

• gt-xsd-core : Basic types defined by XML schema
• gt-xsd-fes : filter 2.0
• gt-xsd-filter : filter 1.0 (used by ogc cat and wfs)
• gt-xsd-kml : keyhole markup language
• gt-xsd-wfs : web feature service
• gt-xsd-wps : web processing service
• gt-xsd-gml3 : geographic markup language 3
• gt-xsd-gml2 : geographinc markup language 2
• gt-xsd-ows : open web services
• gt-xsd-wcs : web coverage service
• gt-xsd-wms : web map service
• gt-xsd-sld : style layer descriptor

XML Development FAQ

Frequently asked questions for binding developers.

• Q: NullPointerException in createURIWithCache when parsing?

  When I try to parse a document, i get the following error:

  java.lang.NullPointerException
      at org.eclipse.emf.common.util.URI.createURIWithCache(URI.java:560)
      at org.eclipse.emf.common.util.URI.createURI(URI.java:494)
      at org.eclipse.xsd.impl.XSDSchemaDirectiveImpl.resolve(XSDSchemaDirectiveImpl.java:389)
      at org.eclipse.xsd.impl.XSDImportImpl.importSchema(XSDImportImpl.java:476)
      at org.eclipse.xsd.impl.XSDSchemaImpl.resolveSchema(XSDSchemaImpl.java:2120)
      at org.eclipse.xsd.impl.XSDSchemaImpl.resolveNamedComponent(XSDSchemaImpl.java:2143)
     ...

  What this means is that somewhere in your instance document, or in a schema it references, a relative uri cannot be resolved to an absolute location.

  Possible solutions:

  • Ensure that the getSchemaLocationResolver method has been implemented for the Configuration class of your schema. The Code Generator can be used to create a schema location resolver specific to your schema.
  • Ensure the Configuration class for your schema declares all the necessary dependencies.

• Q: empty xml element when trying to encode my objects?

  When I try to encode an object ( for instance a polygon ), I get an empty xml element:

  <ogc:Contains>
     <ogc:PropertyName>SERVICEBBOX</ogc:PropertyName>
     <gml:Polygon /> <!-- Polygon isn't well generated  -->
  </ogc:Contains>

  What this means is that the encoding for the element ( Polygon in this case ) has not yet been implemented. Please post the problem to the users list.