geoserver源码学习与扩展——kml/kmz转shapefile文件

geoserver通过工作空间Workspace-数据源DataStore-图层Layer管理地理数据，默认只支持shapefile格式的文件发布，不支持kml/kmz、csv的文件格式，所以存在将这些数据转换为shapefile的需求。

kml/kmz的文件解析基于JavaAPIforKml包完成，该包支持kml和kmz的文件解析；

import de.micromata.opengis.kml.v_2_2_0.Kml;

/*解析kml文件*/
Kml kml = Kml.unmarshal(kmlFile);
processKml(kml,typeName);

/*解析kmz文件*/
Kml[] kmls = Kml.unmarshalFromKmz(kmzFile);
for(Kml kml : kmls){
    processKml(kml,typeName);
}

将Kml转换为shapefile文件也是通过如下2步完成：

1、将Kml转换为FeatureCollection；

2、利用ShapefileDumper类将FeatureCollection转存到硬盘（详见http://www.cnblogs.com/HandyLi/p/8616115.html，不再赘述）；

     /*
      * Kml to FeatureCollection
     */
     private void processKml(Kml kml, String typeName){
         try{
             Feature kmlFeature = kml.getFeature();
             if(kmlFeature instanceof Document){
                 Document doc = (Document)kmlFeature;

                 List<Feature> folderList = doc.getFeature();
                 for(Feature folder: folderList){
                     if(folder instanceof Folder){
                         //one Folder to one SimpleFeatureCollection
                         //get Field info
                         List<String> typeSpec = new ArrayList<String>();
                         typeSpec.add("the_geom:Point:srid="+ SRID);// <- the geometry attribute: Point type
                         typeSpec.add("name:String");
                         List<SimpleField> simpleFields = doc.getSchema().get(0).getSimpleField();
                         for(SimpleField simField : simpleFields){
                             String fieldType = simField.getType();
                             String fieldName = simField.getName();
                             typeSpec.add(fieldName + ":" + fieldType);
                         }
                         if(CreateCluster)//add Field:cluster
                             typeSpec.add("cluster:String");
                         String typeSpecs = String.join(",", typeSpec);
                         final SimpleFeatureType TYPE = DataUtilities.createType(typeName,
                                         typeSpecs // all attributes
                                 );

                         SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(TYPE);
                         /*
                          * We create a FeatureCollection into which we will put each Feature created from a record
                          * in the input csv data file
                          */
                         ListFeatureCollection collection = new ListFeatureCollection(TYPE);

                         List<Feature> placeList = ((Folder) folder).getFeature();
                         for(Feature place: placeList){
                             if(place instanceof Placemark){
                                 Geometry kmlGeo = ((Placemark)place).getGeometry();
                                 com.vividsolutions.jts.geom.Geometry jtsGeom = toJTSGeometry(kmlGeo);
                                 featureBuilder.add(jtsGeom);
                                 //Placemark name value
                                 featureBuilder.add(((Placemark)place).getName());

                                 ExtendedData exData = ((Placemark)place).getExtendedData();
                                 List<SimpleData> simDatas = exData.getSchemaData().get(0).getSimpleData();
                                 for(SimpleData sData : simDatas){
                                     featureBuilder.add(sData.getValue());
                                 }
                                 if(CreateCluster)
                                     featureBuilder.add("");    //add cluster field value
                                 SimpleFeature feature = featureBuilder.buildFeature(null);
                                 collection.add(feature);
                             }
                         }
                         // write to shapefile
                         writeShapeFile(collection);
                     }
                 }
             }
         }
         catch(Exception ex){
             throw new IllegalArgumentException("KML parse error: " + ex.getMessage());
         }
     }

注意：toJTSGeometry函数用于将Kml封装的Geometry类转换为JTS库里的Geometry类。

 /*
      * de.micromata.opengis.kml.v_2_2_0.Geometry transform to com.vividsolutions.jts.geom.Geometry
     */
     private com.vividsolutions.jts.geom.Geometry toJTSGeometry(Geometry kmlGeo){
         if(kmlGeo == null)
             return null;

         GeometryFactory geoFactory = JTSFactoryFinder.getGeometryFactory(null);
         if(kmlGeo instanceof MultiGeometry){
             List<com.vividsolutions.jts.geom.Geometry> geoList = new ArrayList<com.vividsolutions.jts.geom.Geometry>();
             List<Geometry> kmlGeoList = ((MultiGeometry)kmlGeo).getGeometry();
             for(Geometry kmlSubGeo : kmlGeoList){
                 geoList.add(toJTSGeometry(kmlSubGeo));
             }
             GeometryCollection gc = geoFactory.createGeometryCollection(geoList.toArray(new com.vividsolutions.jts.geom.Geometry[0]));
             return gc;
         }
         else if(kmlGeo instanceof de.micromata.opengis.kml.v_2_2_0.Point){
             double dLong = ((de.micromata.opengis.kml.v_2_2_0.Point)kmlGeo).getCoordinates().get(0).getLongitude();
             double dLat = ((de.micromata.opengis.kml.v_2_2_0.Point)kmlGeo).getCoordinates().get(0).getLatitude();
             return geoFactory.createPoint(new Coordinate(dLong, dLat));
         }
         else if(kmlGeo instanceof LineString){
             List<Coordinate> geoCoords = new ArrayList<Coordinate>();

             List<de.micromata.opengis.kml.v_2_2_0.Coordinate> coordList = ((LineString)kmlGeo).getCoordinates();
             for(de.micromata.opengis.kml.v_2_2_0.Coordinate kmlCoord : coordList){
                 double dLong = kmlCoord.getLongitude();
                 double dLat = kmlCoord.getLatitude();
                 geoCoords.add(new Coordinate(dLong, dLat));
             }
             return geoFactory.createLineString(geoCoords.toArray(new Coordinate[0]));
         }
         else if(kmlGeo instanceof LinearRing){
             List<Coordinate> geoCoords = new ArrayList<Coordinate>();
             List<de.micromata.opengis.kml.v_2_2_0.Coordinate> coordList = ((LinearRing)kmlGeo).getCoordinates();
             for(de.micromata.opengis.kml.v_2_2_0.Coordinate kmlCoord : coordList){
                 double dLong = kmlCoord.getLongitude();
                 double dLat = kmlCoord.getLatitude();
                 geoCoords.add(new Coordinate(dLong, dLat));
             }
             return geoFactory.createLinearRing(geoCoords.toArray(new Coordinate[0]));
         }
         else if(kmlGeo instanceof Polygon){
             List<com.vividsolutions.jts.geom.LinearRing> holes = new ArrayList<com.vividsolutions.jts.geom.LinearRing>();
             com.vividsolutions.jts.geom.LinearRing shell = convertLinearRing(geoFactory, ((Polygon)kmlGeo).getOuterBoundaryIs().getLinearRing());
             List<Boundary> innerBoundaryList = ((Polygon)kmlGeo).getInnerBoundaryIs();
             for(Boundary inner : innerBoundaryList){
                 holes.add(convertLinearRing(geoFactory,inner.getLinearRing()));
             }
             return geoFactory.createPolygon(shell, holes.toArray(new com.vividsolutions.jts.geom.LinearRing[0]));
         }
         else{
             throw new IllegalArgumentException("Unrecognized geometry type: " + kmlGeo);
         }
     }
     private com.vividsolutions.jts.geom.LinearRing convertLinearRing(GeometryFactory geoFactory, LinearRing geometry){
         List<Coordinate> geoCoords = new ArrayList<Coordinate>();
         List<de.micromata.opengis.kml.v_2_2_0.Coordinate> coordList = (geometry).getCoordinates();
         for(de.micromata.opengis.kml.v_2_2_0.Coordinate kmlCoord : coordList){
             double dLong = kmlCoord.getLongitude();
             double dLat = kmlCoord.getLatitude();
             geoCoords.add(new Coordinate(dLong, dLat));
         }
         return geoFactory.createLinearRing(geoCoords.toArray(new Coordinate[0]));

     }