地图坐标分为几种：
1）国际坐标：GPS、WGS84又称为原始坐标，国际公认的世界标准坐标体系；
2）火星坐标：GCJ-02是国家测绘局在02年发布的坐标体系，在国内，至少得使用此坐标体系，比如：google、高德、腾讯地图等；
3）其他特殊坐标：一般都是由火星坐标通过偏移算法计算得出的，比如百度使用的是BD-09坐标，搜狗使用的是自己的搜狗坐标。
国内目前的已知的地图所使用的坐标体系不同，这就造成有时候服务端给的坐标，在不同的地图上显示会存在很大的偏移差。因此需要进行坐标转换。
如高德官方APII坐标转换：https://developer.amap.com/api/webservice/guide/api/convert
工具类转换有1-2米的误差，如需精确位置慎用
public static double pi = 3.1415926535897932384626;
public static double x_pi = 3.14159265358979324 * 3000.0 / 180.0;
public static double a = 6378245.0;
public static double ee = 0.00669342162296594323;
public 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;
}
public 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;
}
public static double[] transform(double lat, double lon) {
if (outOfChina(lat, lon)) {
return new double[]{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 double[]{mgLat,mgLon};
}
/**
* 判断是否在中国
*/
public static boolean outOfChina(double lat, double lon) {
if (lon < 72.004 || lon > 137.8347)
return true;
if (lat < 0.8293 || lat > 55.8271)
return true;
return false;
}
/**
* WGS84转高德
* 35.096775,111.045299
*/
public static double[] gps84_To_Gcj02(double lat, double lon) {
if (outOfChina(lat, lon)) {
return new double[]{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 double[]{mgLat, mgLon};
}
/**
* 高德转84坐标
* */
public static double[] gcj02_To_Gps84(double lat, double lon) {
double[] gps = transform(lat, lon);
double lontitude = lon * 2 - gps[1];
double latitude = lat * 2 - gps[0];
return new double[]{latitude, lontitude};
}
/**
* 高德转百度坐标
*/
public static double[] gcj02_To_Bd09(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 tempLon = z * Math.cos(theta) + 0.0065;
double tempLat = z * Math.sin(theta) + 0.006;
double[] gps = {tempLat,tempLon};
return gps;
}
/**
* 百度转高德坐标
*/
public static double[] bd09_To_Gcj02(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 tempLon = z * Math.cos(theta);
double tempLat = z * Math.sin(theta);
double[] gps = {tempLat,tempLon};
return gps;
}
/**
* 84转百度坐标
*/
public static double[] gps84_To_bd09(double lat,double lon){
double[] gcj02 = gps84_To_Gcj02(lat,lon);
double[] bd09 = gcj02_To_Bd09(gcj02[0],gcj02[1]);
return bd09;
}
/**
* 百度转84坐标
*/
public static double[] bd09_To_gps84(double lat,double lon){
double[] gcj02 = bd09_To_Gcj02(lat, lon);
double[] gps84 = gcj02_To_Gps84(gcj02[0], gcj02[1]);
//保留小数点后六位
gps84[0] = retain6(gps84[0]);
gps84[1] = retain6(gps84[1]);
return gps84;
}
/*
* 保留小数点后六位
*/
private static double retain6(double num){
String result = String .format("%.6f", num);
return Double.valueOf(result);
}
}
本文参考：https://github.com/JackZhouCn/JZLocationConverter
感谢分享