WGS84(GPS)、火星坐标系（GCJ02）、百度地图（BD09）坐标系转换Java代码

在做基于百度地图、高德地图等电子地图做为地图服务的二次开发时，通常需要将具有WGS84等坐标的矢量数据（如行政区划、地名、河流、道路等GIS地理空间数据）添加到地图上面。

然而，在线地图大多使用的是火星坐标系，需要事先将矢量数据转为火星坐标系。本文代码针对WGS84(GPS)、火星坐标系（GCJ02）、百度地图（BD09）坐标系之间互相转换。

public class GpsUtils {private static final double x_pi = 3.1415926535897932384626433832795028841971 * 3000.0 / 180.0;private static final double pi = 3.1415926535897932384626433832795028841971;private static final double a = 6378245.0;private static final double ee = 0.00669342162296594323;/*** 84 to 火星坐标系 (GCJ-02) World Geodetic System ==> Mars Geodetic System** @param lat 纬度* @param lon 经度*/public static Gps wgs84ToGcj02(double lat, double lon) {if (outOfChina(lat, lon)) {return new Gps(lat, lon);}double dLat = transformLat(lon - 105.0, lat - 35.0);double dLon = transformLon(lon - 105.0, lat - 35.0);double radLat = lat / 180.0 * pi;double magic = Math.sin(radLat);magic = 1 - ee * magic * magic;double sqrtMagic = Math.sqrt(magic);dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);double mgLat = lat + dLat;double mgLon = lon + dLon;return new Gps(mgLat, mgLon);}/*** WGS84 To 百度BD09** @param lat 纬度* @param lon 经度* @return*/public static Gps wgs84ToBd09(double lat, double lon) {var gps = wgs84ToGcj02(lat, lon);return gcj02ToBd09(gps.getLat(), gps.getLon());}/*** 火星坐标系 (GCJ-02) to 84** @param lat 纬度* @param lon 经度* @return*/public static Gps gcj02ToGps84(double lat, double lon) {Gps gps = transform(lat, lon);double longtitude = lon * 2 - gps.getLon();double latitude = lat * 2 - gps.getLat();return new Gps(latitude, longtitude);}/*** 火星坐标系 (GCJ-02) 与百度坐标系 (BD-09) 的转换算法 将 GCJ-02 坐标转换成 BD-09 坐标** @param lat 纬度* @param lon 经度*/public static Gps gcj02ToBd09(double lat, double lon) {double x = lon, y = lat;double z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * x_pi);double theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * x_pi);double bd_lon = z * Math.cos(theta) + 0.0065;double bd_lat = z * Math.sin(theta) + 0.006;return new Gps(bd_lat, bd_lon);}/*** 火星坐标系 (GCJ-02) 与百度坐标系 (BD-09) 的转换算法,将 BD-09 坐标转换成GCJ-02 坐标** @param lat 纬度* @param lon 经度* @return*/public static Gps bd09ToGcj02(double lat, double lon) {double x = lon - 0.0065, y = lat - 0.006;double z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * x_pi);double theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * x_pi);double ggLon = z * Math.cos(theta);double ggLat = z * Math.sin(theta);return new Gps(ggLat, ggLon);}/*** (BD-09)-->84** @param lat 纬度* @param lon 经度* @return*/public static Gps bd09ToWgs84(double lat, double lon) {Gps gcj02 = bd09ToGcj02(lat, lon);Gps map84 = gcj02ToGps84(gcj02.getLat(),gcj02.getLon());return map84;}/*** 将wgs84转换到指定坐标系** @param coordType 0=wgs84,1=百度坐标系,2=高德,腾讯，火星坐标系* @param lat       纬度* @param lon       经度* @return 转换后的坐标，为null表示转换失败*/public static Gps wgs84To(int coordType, double lat, double lon) {switch (coordType) {case 1: {return wgs84ToBd09(lat, lon);}case 2: {return wgs84ToGcj02(lat, lon);}default:return null;}}private static Gps transform(double lat, double lon) {if (outOfChina(lat, lon)) {return new Gps(lat, lon);}double dLat = transformLat(lon - 105.0, lat - 35.0);double dLon = transformLon(lon - 105.0, lat - 35.0);double radLat = lat / 180.0 * pi;double magic = Math.sin(radLat);magic = 1 - ee * magic * magic;double sqrtMagic = Math.sqrt(magic);dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);double mgLat = lat + dLat;double mgLon = lon + dLon;return new Gps(mgLat, mgLon);}private static double transformLat(double x, double y) {double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y+ 0.2 * Math.sqrt(Math.abs(x));ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;ret += (20.0 * Math.sin(y * pi) + 40.0 * Math.sin(y / 3.0 * pi)) * 2.0 / 3.0;ret += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0;return ret;}private static double transformLon(double x, double y) {double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1* Math.sqrt(Math.abs(x));ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;ret += (20.0 * Math.sin(x * pi) + 40.0 * Math.sin(x / 3.0 * pi)) * 2.0 / 3.0;ret += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0* pi)) * 2.0 / 3.0;return ret;}
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