我用Geotools 8.4爲OS Mastermap寫了一個GML文件解析器。有一部分我仍然有問題。在XSD的這sniplet:如何使用Geotools編寫GML解析器?
<complexType name="RoadLinkType">
<complexContent>
<extension base="osgb:AbstractFeatureType">
<sequence>
<element name="polyline" type="gml:GeometryPropertyType"/>
<element name="directedNode" type="osgb:directedNodeAssociationType" minOccurs="2" maxOccurs="2"/>
</sequence>
</extension>
</complexContent>
</complexType>
的部分來自GML文件:
<osgb:RoadLink fid='osgb4000000023204016'>
<osgb:polyline>
<gml:LineString srsName='osgb:BNG'>
<gml:coordinates>516609.000,257678.000 516615.000,257733.000 516618.000,257786.000</gml:coordinates>
</gml:LineString>
</osgb:polyline>
<osgb:directedNode orientation='-' xlink:href='#osgb4000000027916595'/>
<osgb:directedNode orientation='+' gradeSeparation='1' xlink:href='#osgb4000000028203009'/>
</osgb:RoadLink>
它被解析接近直角,即折線是正確的(我得到一個類com.vividsolutions.jts.geom .LineString),但我只得到一個(而不是兩個)directedNode。
我的代碼:
GML gml = new GML(Version.GML3);
CRSAuthorityFactory crsFac = ReferencingFactoryFinder.getCRSAuthorityFactory("EPSG", null);
CoordinateReferenceSystem osgbCrs = crsFac.createCoordinateReferenceSystem("EPSG:27700");
gml.setCoordinateReferenceSystem(osgbCrs);
SimpleFeatureIterator iter = gml.decodeFeatureIterator(in);
while (iter.hasNext())
{
SimpleFeature feature = iter.next();
System.out.println("id: " + feature.getID());
System.out.println("polyline: " + feature.getAttribute("polyline"));
Object dnode = feature.getAttribute("directedNode");
System.out.println("directedNode: '" + dnode + "'\t" + dnode.getClass());
}
和輸出:
id: osgb4000000023204016
polyline: LINESTRING (516609 257678, 516615 257733, 516618 257786)
directedNode: '{orientation=-, href=#osgb4000000027916595}' class java.util.HashMap
我在做什麼錯?爲什麼我不能同時使用directedNode?我怎樣才能綁定到真正的Java對象?
我也發佈在gis.stackexchange上,因爲我不確定它更適合哪裏:http://gis.stackexchange.com/questions/52418/how-to-write-gml-parser-with-geotools – Burkhard 2013-02-20 13:04:25