Java代码如何进行中国行政区划多边中生成随机点

import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.google.common.geometry.*;
import org.springframework.core.io.ClassPathResource;

import java.io.IOException;
import java.io.InputStream;
import java.util.*;

public class GEOJsonUtils {

    public static Map<String, S2Polygon> jsonList = new HashMap<>();

    public static S2Polygon readJson(String code) throws IOException {

        if(jsonList.containsKey(code)){

        }else{
            String name = code.substring(0,4) + "00.json";
            ClassPathResource classPathResource = new ClassPathResource("json/"+name);
            InputStream inputStream =classPathResource.getInputStream();
            byte[] content = new byte[10240];
            StringBuffer sb = new StringBuffer();
            int len = 0;
            while ((len = inputStream.read(content)) > 0){
                sb.append(new String(content,0, len));
            }
            JSONObject parse = JSONObject.parseObject(sb.toString());
            JSONArray features = parse.getJSONArray("features");
            for (int i = 0 ; i < features.size(); i++) {
                JSONObject feature = (JSONObject)features.get(i);
                String id = feature.getString("id");
                JSONObject geometry = feature.getJSONObject("geometry");
                JSONArray encodeOffsets = geometry.getJSONArray("encodeOffsets");
                JSONArray coordinates = geometry.getJSONArray("coordinates");
                String type = geometry.getString("type");
                if("Polygon".equals(type)){
                    List<double[]> floats = decodePolygon(coordinates.getString(0),
                            new double[]{encodeOffsets.getJSONArray(0).getDoubleValue(0), encodeOffsets.getJSONArray(0).getDoubleValue(1)});
                    List<S2Point> vertices = new ArrayList<>();
                    for (double[] item :floats) {
                        vertices.add(S2LatLng.fromDegrees(item[1],item[0]).toPoint());
                    }

                    S2Loop s2Loop = new S2Loop(vertices);
                    //创建多边形
                    S2Polygon polygon = new S2Polygon(s2Loop);
                    s2Loop.normalize();
                    jsonList.put(id,polygon);
                }else if("MultiPolygon".equals(type)){
                    List<S2Loop> loops = new ArrayList<>();
                    for(int j = 0 ; j < coordinates.size() ; j++){
                        List<double[]> floats = decodePolygon(coordinates.getString(j),
                                new double[]{encodeOffsets.getJSONArray(j).getJSONArray(0).getDoubleValue(0),
                                        encodeOffsets.getJSONArray(j).getJSONArray(0).getDoubleValue(1)});
                        List<S2Point> vertices = new ArrayList<>();
                        for (double[] item :floats) {
                            S2LatLng s2LatLng = S2LatLng.fromDegrees(item[1],item[0]);
                            S2Point s2Point = s2LatLng.toPoint();
                            vertices.add(s2Point);
                        }
                        S2Loop s2Loop = new S2Loop(vertices);
                        loops.add(s2Loop);
                        s2Loop.normalize();
                    }
                    //创建多边形
                    S2Polygon polygon = new S2Polygon(loops);
                    jsonList.put(id,polygon);
                }
            }
            if(!jsonList.containsKey(code)){
                jsonList.put(code, null);
            }
        }

        return jsonList.get(code);
    }

    public static S2LatLng randomPoint(S2Polygon polygon){

        for(int i = 0 ; i < polygon.numLoops() ; i++){
            S2LatLngRect rect = polygon.loop(i).getRectBound();
            S2LatLng s2LatLng1 = new S2LatLng(rect.lo().toPoint());
            S2LatLng s2LatLng2 = new S2LatLng(rect.hi().toPoint());

            double minX = 0;
            double minY = 0;
            double maxX = 0;
            double maxY = 0;

            if(s2LatLng1.lat().degrees() > s2LatLng2.lat().degrees()){
                maxX = s2LatLng1.lat().degrees();
                minX = s2LatLng2.lat().degrees();
            }else{
                maxX = s2LatLng2.lat().degrees();
                minX = s2LatLng1.lat().degrees();
            }
            if(s2LatLng1.lng().degrees() > s2LatLng2.lng().degrees()){
                maxY = s2LatLng1.lng().degrees();
                minY = s2LatLng2.lng().degrees();
            }else{
                maxY = s2LatLng2.lng().degrees();
                minY = s2LatLng1.lng().degrees();
            }

            Random r = new Random();
            S2Point rPoint = new S2Point();

            for(int j = 0 ; j < 10 ; j++){
                double x = r.nextDouble()*(maxX - minX) + minX;
                double y = r.nextDouble()*(maxY - minY) + minY;
                rPoint = S2LatLng.fromDegrees(x, y).toPoint();

                if(polygon.contains(rPoint)){
                    S2LatLng s2LatLng = new S2LatLng(rPoint);
                    return s2LatLng;
                }
            }

            if(i == polygon.numLoops() - 1){
                i = 0;
            }
        }

        return null;
    }

    public static List<double[]> decodePolygon(String coordinate, double[] encodeOffsets){
        List<double[]> result = new ArrayList<>();
        double prevX = encodeOffsets[0];
        double prevY = encodeOffsets[1];

        for (int i = 0; i < coordinate.length(); i += 2) {
            int x = coordinate.charAt(i) - 64;
            int y = coordinate.charAt(i + 1) - 64;
            x = (x >> 1) ^ (-(x & 1));
            y = (y >> 1) ^ (-(y & 1));
            x += prevX;
            y += prevY;

            prevX = x;
            prevY = y;
            result.add(new double[]{x / 1024d, y / 1024d});
        }
        return result;
    }

}