sysu_emap/src/main/java/com/sysu/admin/utils/shape/GeoCastUtil.java

package com.sysu.admin.utils.shape;

import org.geotools.geojson.geom.GeometryJSON;
import org.geotools.geometry.jts.WKTWriter2;
import org.locationtech.jts.geom.*;
import org.opengis.feature.type.GeometryDescriptor;

import java.io.IOException;
import java.io.StringReader;

public class GeoCastUtil {

    private static WKTWriter2 wktReader2 = new WKTWriter2();

    public static String geomToWkt(Geometry geometry){
        return wktReader2.write(geometry);
    }

    private static GeometryCollection castGeometryCollection2(GeometryJSON fjson, GeometryCollection geometryCollection) throws IOException {
        if (geometryCollection.getGeometryType().equals("GeometryCollection")) {
            return geometryCollection;
        }
        String[] geometriesJsonArray = new String[geometryCollection.getNumGeometries()];
        int length = 0;
        for(int i=0; i< geometryCollection.getNumGeometries(); i++){
            Geometry geometry = geometryCollection.getGeometryN(i);
            geometriesJsonArray[i] = fjson.toString(geometry);
            length += geometriesJsonArray[i].length();
        }
        StringBuffer result = new StringBuffer(length + 100);
        result.append("{\"type\": \"GeometryCollection\",\"geometries\": [");
        result.append(geometriesJsonArray[0]);
        for(int i=1;i< geometriesJsonArray.length;i++){
            result.append(",").append(geometriesJsonArray[i]);
        }
        result.append("]}");
        return fjson.readGeometryCollection(new StringReader(result.toString()));
    }

    public static GeometryCollection castGeometryCollection(GeometryJSON fjson, Geometry geometry) throws IOException {
        if (geometry.getGeometryType().equals("GeometryCollection")) {
            return (GeometryCollection)geometry;
        }
        if (geometry instanceof GeometryCollection) {
            return castGeometryCollection2(fjson, (GeometryCollection)geometry);
        }
        String geometryJson = fjson.toString(geometry);
        StringBuffer result = new StringBuffer(geometryJson.length() + 100);
        result.append("{\"type\": \"GeometryCollection\",\"geometries\": [");
        result.append(geometryJson);
        result.append("]}");
        return fjson.readGeometryCollection(new StringReader(result.toString()));
    }

    public static Geometry readGeometry(Object input, String type, GeometryJSON gjson) throws IOException {
        switch(type){
            case "Point":
                return gjson.readPoint(input);
            case "MultiPoint":
                return gjson.readMultiPoint(input);
            case "LineString":
                return gjson.readLine(input);
            case "MultiLineString":
                return gjson.readMultiLine(input);
            case "Polygon":
                return gjson.readPolygon(input);
            case "MultiPolygon":
                return gjson.readMultiPolygon(input);
        }
        return null;
    }

}