原始GPS坐标（WGS-84）转成百度的经纬度，零误差

前言：在博客上找了很多，也看了很多浏览度高的，但是一测试，还是有几百米或者几十米的误差

于是我就借鉴几个博客做了调整，经度度与百度手机定位几乎一致。

借鉴博客地址：https://blog.csdn.net/coolypf/article/details/8569813

                         还有一个博客：找不到了，看到很多博客，都是转载或者抄袭借鉴，暂时没找到原文，找到了再放上来

 

一、84 to 火星坐标系 (GCJ-02) to 百度地图坐标

/**
 * @Author zr
 * @Date 2019-08-29 17:03
 * @Version 2.0
 */
public class BdMapUtil {
    /** 圆周率 */
    public static double pi = 3.1415926535897932384626;
    public static double a = 6378245.0;
    public static double ee = 0.00669342162296594323;
    private static double x_pi = 3.14159265358979324 * 3000.0 / 180.0;

    /**
     * 得到百度地图经纬度
     *
     * @author zr
     * @date 2019-09-09
     * @param lat WGS-84 gps的纬度
     * @param lon WGS-84 gps的经度
     * @return com.construn.vehicle.message.util.Gps
     */
    public static Gps getBd09(double lat, double lon){
        //得到火星坐标经纬度
        Gps gps = gps84ToGcj02(lat, lon);
        if(gps ==null){
            return null;
        }
        //得到百度坐标经纬度
        return gcj02ToBd09(gps.getWgLat(), gps.getWgLon());
    }
    /**
     * 火星坐标系 (GCJ-02)转百度地图坐标系
     *
     * @author zr
     * @date 2019-09-09
     * @param  * @param gg_lat
     * @param gg_lon
     * @return void
     */
    private static Gps gcj02ToBd09(double gg_lat, double gg_lon) {
        double x = gg_lon, y = gg_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);
    }
    /**
      * 84 to 火星坐标系 (GCJ-02)
      *
      * @author zr
      * @date 2019-09-09
      * @param  * @param lat
      * @param lon
      * @return void
      */
    private static Gps gps84ToGcj02(double lat, double lon) {
        if (outOfChina(lat, lon)) {
            return null;
        }
        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);
    }

    /**
     * 判断有没有超过中国区
     *
     * @author zr
     * @date 2019-09-09
     * @param  * @param lat
     * @param lon
     * @return boolean
     */
    private 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;
    }

    /**
     * 处理纬度
     *
     * @author zr
     * @date 2019-09-09
     * @param  * @param x
     * @param y
     * @return double
     */
    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;
    }

    /**
     * 处理经度
     *
     * @author zr
     * @date 2019-09-09
     * @param  * @param x
     * @param y
     * @return double
     */
    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;
    }
}

Gps类

import lombok.Getter;
import lombok.Setter;

/**
 * gps 经纬度坐标类
 *
 * @Author zr
 * @Date 2019-09-09 19:12
 * @Version 2.0
 */
@Getter
@Setter
public class Gps {
    private double wgLat;
    private double wgLon;

    public Gps() {
    }
    public Gps(double wgLat, double wgLon) {
        setWgLat(wgLat);
        setWgLon(wgLon);
    }
    @Override
    public String toString() {
        return "Gps{" +
                "wgLat=" + wgLat +
                ", wgLon=" + wgLon +
                '}';
    }
}

二、说明下、百度的地图加密原始gps地理坐标是这样的：百度地图加密的是 火星坐标系 (GCJ-02)，而GCJ-02加密的是原始gps坐标系。所以从原始gps坐标，到百度地图坐标，顺序是WGS-84 --> GCJ-02 --> BD-09