[Geotools-devel] Fwd: Re: [Geoserver-users] Re: Geoserver Question

[Chris H. <ch...@op...>]

Forwarding to geotools-devel list, since I'm past my knowledge about gml
at this point.

Chris

----- Forwarded message from Adrien Anselme <ada...@gm...> -----
    Date: Wed, 13 Apr 2005 12:09:29 +0900
    From: Adrien Anselme <ada...@gm...>
Reply-To: Adrien Anselme <ada...@gm...>
 Subject: Re: [Geoserver-users] Re: Geoserver Question
      To: Chris Holmes <ch...@op...>

Hi,

> Ok, first off, I have never tried out the gml datastore, so I can only
> give you guesses.  If you could report back success or failures that
> would be great.
>
> The place to get started is in geotools.  Get a 2.1 version, and try
out
> the gml datastore, in plugins/.  GeoServer is completely decoupled
from
> the datastores, it interacts with them through the factory interface,
> see
>
http://svn.geotools.org/geotools/trunk/gt/plugin/gml/src/org/geotools/dat=
a/gml/GMLDataStoreFactory.java
> It looks like the file needs to end in either .xml or .gml.  And you
> need to specify the url to the file.  Shapefile has examples, see
>
http://geoserver.sourceforge.net/documentation/user/datastores.html#shape=
file
> and just change the file name to the one you are using.
>
> As for specifying the XML schema file, you should do so in the gml
file
> itself, the parser will resolve the schemaLocation (definitely need to
> specify it), and parse the Schema file.  So be _sure_ your xml file
> points to its schema file.


I made some tries with the GML datastore but I still can't get anything
to work.

I created a custom simple GML file and its Schema using XMLSpy, so I'm
sure that the files are correct and validate.
The only thing I have to change after saving my xml file in xmlspy is
the path to the schema file. Xmlspy wants something like
D:\taf\city.xml whereas Geotools expects an URL like
file:/D:/taf/city.xml .

I then wrote a test code based on the shpDataStore samples of Geotools'
wiki :

try {

  //fileSelect is a private method to open a dialog and get a file
  URL shapeURL =3D fileSelect("gml","GML File","D:\\taf\\city.xml");

  //datastore creation
  GMLDataStoreFactory facto =3D new GMLDataStoreFactory();
  GMLDataStore store =3D (GMLDataStore)facto.createDataStore(shapeURL);
  FeatureType ft =3D store.getSchema();

  //is supposed to display the featuretypes of the datastore
  for (int i =3D 0; i < ft.getAttributeCount(); i++) {    //THIS IS LINE
139
    AttributeType at =3D ft.getAttributeType( i );
    if (!Geometry.class.isAssignableFrom(at.getType()))
      System.out.print(at.getType().getName() + "\t");
  }
} catch (IOException ie) {
  System.err.println("IOException: " + ie.getMessage());
}

But I get an exception that I don't understand :

Exception in thread "main" java.lang.NullPointerException
	at adrien.tests.geotools.Test.testGml(Test.java:139)
	at adrien.tests.geotools.Test.main(Test.java:30)
2005. 4. 13 =EC=98=A4=EC =84 11:40:04 org.geotools.xml.XMLSAXHandler endE=
lement
=EA=B2=BD=EA=B3 : Stopping
2005. 4. 13 =EC=98=A4=EC =84 11:40:04 org.geotools.xml.XMLSAXHandler endE=
lement
=EA=B2=BD=EA=B3 : Line 25 Col 15
org.geotools.xml.gml.FCBuffer$StopException: Stopping
	at
org.geotools.xml.gml.GMLComplexTypes$AbstractFeatureType.stream(GMLComple=
xTypes.java:4179)
	at
org.geotools.xml.gml.GMLComplexTypes$AbstractFeatureType.getValue(GMLComp=
lexTypes.java:4096)
	at
org.geotools.xml.handlers.xsi.ComplexTypeHandler$DefaultComplexType.getVa=
lue(ComplexTypeHandler.java:1064)
	at
org.geotools.xml.handlers.ComplexElementHandler.endElement(ComplexElement=
Handler.java:184)
	at org.geotools.xml.XMLSAXHandler.endElement(XMLSAXHandler.java:209)
	at
com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(U=
nknown
Source)
	at
com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanEndE=
lement(Unknown
Source)
	at
com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$Fr=
agmentContentDispatcher.dispatch(Unknown
Source)
	at
com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.sc=
anDocument(Unknown
Source)
	at
com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unkno=
wn
Source)
	at
com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unkno=
wn
Source)
	at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown
Source)
	at
com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(Unknow=
n
Source)
	at javax.xml.parsers.SAXParser.parse(Unknown Source)
	at javax.xml.parsers.SAXParser.parse(Unknown Source)
	at
org.geotools.xml.DocumentFactory.getInstance(DocumentFactory.java:108)
	at
org.geotools.xml.DocumentFactory.getInstance(DocumentFactory.java:81)
	at org.geotools.xml.gml.FCBuffer.run(FCBuffer.java:335)



(Don't pay attention to the korean caracters =EC=98=A4=EC =84 that mean
"wednesday" ;) )

I tested different things but I almost always get the same exception
(nullPointer). Can't use any of the methods of the GMLDataStore class
without raising an exception, appart from the getSchema that seems to
work.

Any idea?

I attached the .xml and .xsd files used for the example.

--=20
Adrien ANSELME
--------------
Etudiant en G=C3=A9nie Informatique =C3  l'UTC
http://www.utc.fr

page professionnelle (cv): http://wwwetu.utc.fr/~adanselm/
page perso: http://adrien.adan.free.fr
id jabber : aan...@am...

----- End forwarded message -----




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