百度平面坐标(墨卡托坐标)转百度坐标，转高德坐标

直接上代码：

public class CoodinateCovertor {
    private static Double EARTHRADIUS = 6370996.81;
    private static Double[] MCBAND = {12890594.86, 8362377.87, 5591021d, 3481989.83, 1678043.12, 0d};
    private static Double[] LLBAND = {75d, 60d, 45d, 30d, 15d, 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}};
    private static Double[][] LL2MC = {{-0.0015702102444, 111320.7020616939, 1704480524535203d, -10338987376042340d, 26112667856603880d, -35149669176653700d, 26595700718403920d, -10725012454188240d, 1800819912950474d, 82.5}, {0.0008277824516172526, 111320.7020463578, 647795574.6671607, -4082003173.641316, 10774905663.51142, -15171875531.51559, 12053065338.62167, -5124939663.577472, 913311935.9512032, 67.5}, {0.00337398766765, 111320.7020202162, 4481351.045890365, -23393751.19931662, 79682215.47186455, -115964993.2797253, 97236711.15602145, -43661946.33752821, 8477230.501135234, 52.5}, {0.00220636496208, 111320.7020209128, 51751.86112841131, 3796837.749470245, 992013.7397791013, -1221952.21711287, 1340652.697009075, -620943.6990984312, 144416.9293806241, 37.5}, {-0.0003441963504368392, 111320.7020576856, 278.2353980772752, 2485758.690035394, 6070.750963243378, 54821.18345352118, 9540.606633304236, -2710.55326746645, 1405.483844121726, 22.5}, {-0.0003218135878613132, 111320.7020701615, 0.00369383431289, 823725.6402795718, 0.46104986909093, 2351.343141331292, 1.58060784298199, 8.77738589078284, 0.37238884252424, 7.45}};


    private static double x_pi = 3.14159265358979324 * 3000.0 / 180.0;


    /**
     * 墨卡托坐标转经纬度坐标
     *
     * @param x
     * @param y
     * @return
     */
    public static Map 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 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 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 location = new HashMap();
        location.put("x", xTemp);
        location.put("y", yTemp);
        return location;
    }


    /**
     * 对double类型数据保留小数点后多少位
     * 高德地图转码返回的就是 小数点后6位，为了统一封装一下
     *
     * @param digit 位数
     * @param in    输入
     * @return 保留小数位后的数
     */
    static double dataDigit(int digit, double in) {

        return new BigDecimal(in).setScale(6, BigDecimal.ROUND_HALF_UP).doubleValue();

    }

    /**
     * 将火星坐标转变成百度坐标
     *
     * @param lngLat_gd 火星坐标（高德、腾讯地图坐标等）
     * @return 百度坐标
     */

    public static LngLat bd_encrypt(LngLat lngLat_gd) {
        double x = lngLat_gd.getLongitude(), y = lngLat_gd.getLantitude();
        double z = sqrt(x * x + y * y) + 0.00002 * sin(y * x_pi);
        double theta = atan2(y, x) + 0.000003 * cos(x * x_pi);
        return new LngLat(dataDigit(6, z * cos(theta) + 0.0065), dataDigit(6, z * sin(theta) + 0.006));

    }

    /**
     * 将百度坐标转变成火星坐标
     *
     * @param lngLat_bd 百度坐标（百度地图坐标）
     * @return 火星坐标(高德 、 腾讯地图等)
     */
    static LngLat bd_decrypt(LngLat lngLat_bd) {
        double x = lngLat_bd.getLongitude() - 0.0065, y = lngLat_bd.getLantitude() - 0.006;
        double z = sqrt(x * x + y * y) - 0.00002 * sin(y * x_pi);
        double theta = atan2(y, x) - 0.000003 * cos(x * x_pi);
        return new LngLat(dataDigit(6, z * cos(theta)), dataDigit(6, z * sin(theta)));

    }


    //测试代码
    public static void main(String[] args) {
        Map map = convertMC2LL(Double.parseDouble("13374519.1263999"), Double.parseDouble("3519753.77716"));
        System.out.println("百度坐标："+map);
        Double lng = map.get("lng");
        Double lat = map.get("lat");
        LngLat lngLat_bd = new LngLat(lng, lat);
        System.out.println("高德坐标："+bd_decrypt(lngLat_bd));
    }
}

public class LngLat {
    private double longitude;//经度
    private double lantitude;//维度

    public LngLat() {
    }

    public LngLat(double longitude, double lantitude) {
        this.longitude = longitude;
        this.lantitude = lantitude;
    }

    public double getLongitude() {
        return longitude;
    }

    public void setLongitude(double longitude) {
        this.longitude = longitude;
    }

    public double getLantitude() {
        return lantitude;
    }

    public void setLantitude(double lantitude) {
        this.lantitude = lantitude;
    }

    @Override
    public String toString() {
        return "LngLat{" +
                "longitude=" + longitude +
                ", lantitude=" + lantitude +
                '}';
    }
}