安卓/java后台使用测量方法

/*** 获取中心点* @param wkt 熟知文本* @return [x,y]* @throws ParseException*/public static double[] getCentroid(String wkt) throws ParseException{WKTReader reader = new WKTReader();double[] result = new double[2];Geometry geom = reader.read(wkt);Point centroid = geom.getCentroid();if(!centroid.isEmpty() && centroid.isValid()){result[0] = centroid.getX();result[1] = centroid.getY();}else{throw new IllegalArgumentException("没有有效的中心点");}return result;}/*** 求交集* @param wkt 熟知文本* @param polys 内部集* @throws ParseException */public static String getPolyWithInteraction(String wkt, String[] polys) throws ParseException{GeometryFactory gf = new GeometryFactory();GeometryTransformer gt = new GeometryTransformer();WKTReader reader = new WKTReader();Geometry geom = reader.read(wkt);String type = geom.getGeometryType();if("Polygon".equals(type)){Polygon polygon = (Polygon)geom;int num_rings = polys.length;List<LinearRing> holes = new ArrayList<LinearRing>();for(int i=0;i<num_rings;i++){Polygon interaction = (Polygon)polygon.intersection(reader.read(polys[i]));holes.add((LinearRing)gt.transform(interaction.getExteriorRing()));}Polygon final_geom = gf.createPolygon((LinearRing)polygon.getExteriorRing(), holes.toArray(new LinearRing[num_rings]));return final_geom.toText();}return null;}/*** 计算距离特定点的距离* @param centerX    中心点 经度* @param centerY	 中心点 纬度* @param locationX	  当前经度* @param locationY	  当前纬度* @return*/private static double getDistance(double[] centre,double locationX,double locationY){double centreX = centre[0];double centreY = centre[1];int r =  6362790;double x1 = centreX   * Math.PI/180;double x2 = locationX * Math.PI/180;double y1 = centreY   * Math.PI/180;double y2 = locationY * Math.PI/180;double dx = Math.abs(x1-x2);/*double dy = Math.abs(y1-y2);*/double temp = Math.cos(y1) * Math.cos(y2) * Math.cos(dx) + Math.sin( y1 ) * Math.sin(y2);return r *Math.acos(temp);}