背景:某项目做区域监控,需要内置某些区域的电子围栏。
方案:利用某度接口中墨卡托投影值,进行经纬度转换,入库保存后,让前端获取。
前置数据:区域文案名清单
接口1: 查询某区域的uid
http://api.map.baidu.com/place/v2/search?output=json&scope=2&q=" + area + "®ion=" + city + "&ak=" + ak
area:某区域文案在地图上的文案名
city:该区域所在城市
ak: token
接口2: 获取墨卡托值
http://map.baidu.com/?reqflag=pcmap&coord_type=3&from=webmap&qt=ext&ext_ver=new&l=18&uid=" + uid
uid:接口1获取
墨卡托值是接口2返回值里的geo字段值
墨卡托算法(经纬度转换)
import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class MocatorUtils { private static Double[] MCBAND = {12890594.86, 8362377.87, 5591021d, 3481989.83, 1678043.12, 0d}; private static Double[][] MC2LL = {{1.410526172116255e-8, 0.00000898305509648872, -1.9939833816331, 200.9824383106796, -187.2403703815547, 91.6087516669843, -23.38765649603339, 2.57121317296198, -0.03801003308653, 17337981.2}, {-7.435856389565537e-9, 0.000008983055097726239, -0.78625201886289, 96.32687599759846, -1.85204757529826, -59.36935905485877, 47.40033549296737, -16.50741931063887, 2.28786674699375, 10260144.86}, {-3.030883460898826e-8, 0.00000898305509983578, 0.30071316287616, 59.74293618442277, 7.357984074871, -25.38371002664745, 13.45380521110908, -3.29883767235584, 0.32710905363475, 6856817.37}, {-1.981981304930552e-8, 0.000008983055099779535, 0.03278182852591, 40.31678527705744, 0.65659298677277, -4.44255534477492, 0.85341911805263, 0.12923347998204, -0.04625736007561, 4482777.06}, {3.09191371068437e-9, 0.000008983055096812155, 0.00006995724062, 23.10934304144901, -0.00023663490511, -0.6321817810242, -0.00663494467273, 0.03430082397953, -0.00466043876332, 2555164.4}, {2.890871144776878e-9, 0.000008983055095805407, -3.068298e-8, 7.47137025468032, -0.00000353937994, -0.02145144861037, -0.00001234426596, 0.00010322952773, -0.00000323890364, 826088.5}}; public static List<String> parseJeo(String mocator) { List<String> mocatorList = new ArrayList<String>(); if (null == mocator) return null; /* 拆分数据 */ String[] geos = mocator.split("\\|"); int n = Integer.parseInt(geos[0]); String center = geos[1]; String polylineMoca = geos[2]; //墨卡托坐标 String[] plm = polylineMoca.split("\\;"); /* 获取墨卡托边界 */ String geo = null; if (n == 4) { for (int i = 0; i < plm.length; i++) { String[] geoPaths = plm[i].split("\\-"); if (geoPaths[0].equals("1")) { geo = geoPaths[1]; } } } if(n == 3){ geo = plm[0]; } // 墨卡托坐标解析 String[] geoPolyline = geo.split("\\,"); for (int i = 0; i < geoPolyline.length; i += 2) { mocatorList.add(geoPolyline[i] + "#" + geoPolyline[i + 1]); } return mocatorList; } /** * @param mocator * @return lat lng */ public static List<double[]> calCoords(String mocator, boolean transfer284) { List<String> mocatorList = parseJeo(mocator); List<double[]> coords = new ArrayList<>(); // 封装板块边界 for (int i = 0; i < mocatorList.size(); i++) { String[] coordinate = mocatorList.get(i).split("\\#"); // 墨卡托坐标转换为百度经纬度坐标 Map<String, Double> location = convertMC2LL(Double.parseDouble(coordinate[0]), Double.parseDouble(coordinate[1])); Double lng = location.get("lng"); Double lat = location.get("lat"); double[] aa; if (transfer284) { //百度09坐标系转84坐标系 aa = GpsUtil.bd09Togps84(lat, lng); } else { aa = new double[]{lat, lng}; } coords.add(aa); } return coords; } /** * 墨卡托坐标转经纬度坐标 * * @param x * @param y * @return */ public static Map<String, Double> convertMC2LL(Double x, Double y) { Double[] cF = null; x = Math.abs(x); y = Math.abs(y); for (int cE = 0; cE < MCBAND.length; cE++) { if (y >= MCBAND[cE]) { cF = MC2LL[cE]; break; } } Map<String, Double> location = converter(x, y, cF); location.put("lng", location.get("x")); location.remove("x"); location.put("lat", location.get("y")); location.remove("y"); return location; } private static Map<String, Double> converter(Double x, Double y, Double[] cE) { Double xTemp = cE[0] + cE[1] * Math.abs(x); Double cC = Math.abs(y) / cE[9]; Double yTemp = cE[2] + cE[3] * cC + cE[4] * cC * cC + cE[5] * cC * cC * cC + cE[6] * cC * cC * cC * cC + cE[7] * cC * cC * cC * cC * cC + cE[8] * cC * cC * cC * cC * cC * cC; xTemp *= (x < 0 ? -1 : 1); yTemp *= (y < 0 ? -1 : 1); Map<String, Double> location = new HashMap<String, Double>(); location.put("x", xTemp); location.put("y", yTemp); return location; } }
原文:https://www.cnblogs.com/but999/p/13132368.html