how to get null while parsing xml with geotools parser

Question

I tried to get null value from my xml file such below

  <top:kadastroParselFeature gml:id="KADASTRO_PARSEL.1">
    <top:olcek xsi:nil="true" />
  </top:kadastroParselFeature>

but my parser throws such an exception :

java.lang.RuntimeException: Parsing failed for kadastroParselFeature: java.lang.NullPointerException
at org.geotools.xml.impl.ParseExecutor.visit(ParseExecutor.java:164)
at org.geotools.xml.impl.BindingWalker$BindingExecutionChain.execute(BindingWalker.java:220)
at org.geotools.xml.impl.BindingWalker.walk(BindingWalker.java:186)
at org.geotools.xml.impl.ElementHandlerImpl.endElement(ElementHandlerImpl.java:236)
at org.geotools.xml.impl.ParserHandler.endElement(ParserHandler.java:719)

My parser configuration like this :

   org.geotools.xml.Configuration configuration = new org.geotools.gml2.GMLConfiguration();

   org.geotools.xml.Parser parser = new org.geotools.xml.Parser( configuration );

   parser.setFailOnValidationError(false);

   HashMap<Object, Object> parsedMap = (HashMap<Object, Object>) parser.parse( isx);

if I remove xsi:nill="true" from element it returns ""(empty string) but i need null .

there is a usage of my parser at http://docs.geotools.org/stable/userguide/library/xml/geometry.html

Answer 1

I found a solution for my work the problem at my gml writer version if i changed the version from gml2 to gml3 the problem not seen. and ı changed my parser config. like this

       org.geotools.xml.Configuration configuration = new org.geotools.gml3.ApplicationSchemaConfiguration("sampleURL", "sample.xsd");


       org.geotools.xml.Parser parser = new org.geotools.xml.Parser( configuration );