Morning Robert; I am just going to be the first to reply to you - others are going to need to fill in the details (hint change the subject line as we explore different topics). > Hello, > > In my quest to execute XQuery with GIS data, I found a problem with > WKTReader / WKTWriter. > Aside: We have had some luck using JXPath behind an implementation of PropertyAccessor - as used by the Filter / Expression code. If I remember correctly XPath support is part of XQuery? > In the first version of my application, I let the user to write a WKT > Polygon to create a criteria for the request (for example : return all > polygon which contains the POINT (278415 187644) ). I used this point to > create my XQuery. So I used the class WKTReader to create a Geometry > object, which I serialize again with org.geotools.xml.Encoder : > > The point serialized in GML is : > <gml:Point xmlns:gml="http://www.opengis.net/gml"; > xmlns:xlink="http://www.w3.org/1999/xlink";> > <gml:coord><gml:X>278415.0</gml:X><gml:Y>187644.0</gml:Y></gml:coord> > </gml:Point> > > As you see, the srsName is not present. If I execute the request, > nothing is returned. If I add the attribute srsName="osgb:BNG" for > gml:Point, I get my objects. > I am not sure what authority "osgb" is? The "referencing stuff" depends on implementations of AuthorityFactory: - http://docs.codehaus.org/display/GEOTDOC/07+Referencing - http://docs.codehaus.org/display/GEOTDOC/Referencing+Developers+Guide
I don't recommend making up a new authority - simply because they are used to communicate what the information means between applications; so you would at least need to teach several applications about your authority. > Is it a bug ? Perhaps, I misunderstood something? > Perhaps - usually the referencing stuff is provided by some industry standards body; I am used to them being in the format "AUTHORITYID:CODE" ... where code is usually a number. In GML the srs information can occur in a geometry or in a parent (like parent feature or parent feature collection); as such I bet we need to specify this as an extra parameter to the transform code? - http://docs.codehaus.org/display/GEOTDOC/Referencing+Developers+Guide Yes I have stuffed the information into geometry.getUserObject() as a String; and sometimes the code into the geometry.getSRID() but this is convention only; really you need to know the context of your geometry in order to understand it. > I tried to put the SRS ID in the Geometry without success : > geo.setSRID(4326); > > The SR ID is not the second part of the srsName (authority:ID) ? > How can I store the srsName in my GML ? > transform.setSrsName( String ) - as shown on the above page... > When I get the result, I need to parse the GML fragment. I did it but > the osgb:BNG authority is not found. In google, I found this issue : > http://jira.codehaus.org/browse/GEOT-1307 > Cool - well you can make a new AuthorityFactory; why not start up a new unsupported module for this work? > How can I declare an authority ? > But I get > org.opengis.referencing.FactoryException: Les extensions de Geotools > sont requises pour l'opération "getIdentifiedObjectFinder". > which means The Geotools extensions are required for the operation > "getIdentifiedObjectFinder". > .. right - it wants to have a factory that encodes all the information defined by the Ordance Survey into java code (or database form). > Thanks in advance for your help. > Have fun, Jody ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Geotools-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-devel
