计算两个GPS坐标点的距离

计算两个GPS坐标点的距离，第一个参数是第一个点的维度，第二个参数是第一个点的经度

http://yuninglovekefan.blog.sohu.com/235655696.html

/**
 * 
 */
package utils;

/**
 * 坐标计算的工具类
 * 
 * @author ywf
 * 
 */
public class PositionUtils {

    private static final double EARTH_RADIUS = 6371.004;
    static double pi = 3.14159265358979324;
    static double a = 6378245.0;
    static double ee = 0.00669342162296594323;
    static double x_pi = 3.14159265358979324 * 3000.0 / 180.0;

    /**
     * 将一个点坐标转换为百度坐标
     * 
     * @param point
     */
    public static double[] transBMapPosition(double wgLat, double wgLon) {
        if (wgLat == 0 || wgLon == 0)
            return null;
        double[] MarsGPS = transform(wgLat, wgLon);
        double x = MarsGPS[1], y = MarsGPS[0];
        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);
        MarsGPS[0] = z * Math.sin(theta) + 0.0060068;
        MarsGPS[1] = z * Math.cos(theta) + 0.0065054;
        return MarsGPS;
    }

    // World Geodetic System ==> Mars Geodetic System
    private static double[] transform(double wgLat, double wgLon) {
        double[] ret = new double[2];
        ret[0] = wgLat;
        ret[1] = wgLon;
        double mgLat, mgLon;
        if (outOfChina(wgLat, wgLon)) {
            mgLat = wgLat;
            mgLon = wgLon;
            ret[0] = mgLat;
            ret[1] = mgLon;
            return ret;
        }
        double dLat = transformLat(wgLon - 105.0, wgLat - 35.0);
        double dLon = transformLon(wgLon - 105.0, wgLat - 35.0);
        double radLat = wgLat / 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);
        mgLat = wgLat + dLat;
        mgLon = wgLon + dLon;

        ret[0] = mgLat;
        ret[1] = mgLon;
        return ret;
    }

    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;
    }

    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;
    }

    /**
     * @param lat1
     *            纬度
     * @param lng1
     *            经度
     * @param lat2
     *            纬度
     * @param lng2
     *            经度
     * @return
     */
    public static double getDistance(double lat1, double lng1, double lat2,
            double lng2) {
        double radLat1 = lat1;
        double radLat2 = lat2;
        double a = lng1 - lng2;

        double s = Math.acos(Math.cos(radLat1) * Math.cos(radLat2)
                * Math.cos(a) + Math.sin(radLat1) * Math.sin(radLat2));
        s = s * EARTH_RADIUS * 1000 * Math.PI / 180.0;
        return s;
    }
    
    /**
     * @param lat_a 维度
     * @param lng_a 经度
     * @param lat_b
     * @param lng_b
     * @return
     */
    private static double gps2m(double lat_a, double lng_a, double lat_b, double lng_b) { 

        double pk = (double) (180/3.14169); 

        double a1 = lat_a / pk; 

        double a2 = lng_a / pk; 

        double b1 = lat_b / pk; 

        double b2 = lng_b / pk; 

        double t1 = Math.cos(a1)*Math.cos(a2)*Math.cos(b1)*Math.cos(b2); 

        double t2 = Math.cos(a1)*Math.sin(a2)*Math.cos(b1)*Math.sin(b2); 

        double t3 = Math.sin(a1)*Math.sin(b1); 

        double tt = Math.acos(t1 + t2 + t3); 

        return 6366000*tt; 

        }

    /**
     * 每个点元素为经度，纬度
     * 
     * @param node1
     * @param node2
     * @return
     */
    public static double getDistince(double[] node1, double[] node2) {
        return getDistance(node1[1], node1[0], node2[1], node2[0]);
    }
    private static double rad(double d)
    {
     return d * Math.PI / 180.0;
    }

    public static double GetDistance(double lat1, double lng1, double lat2, double lng2)
    {
     double radLat1 = rad(lat1);
     double radLat2 = rad(lat2);
     double a = radLat1 - radLat2;
     double b = rad(lng1) - rad(lng2);
     double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a/2),2) +
     Math.cos(radLat1)*Math.cos(radLat2)*Math.pow(Math.sin(b/2),2)));
     s = s * EARTH_RADIUS*1000;
     //s = Math.round(s * 10000) / 10000;
     return s;
    }
    public static void main(String[] args) {
        double distance = getDistance(36.74114227294922, 119.14092225294847,  36.70890173661081, 119.12844896818463);
        System.out.println(distance);
        System.out.println(gps2m(36.74114227294922, 119.14092225294847,  36.70890173661081, 119.12844896818463));
        System.out.println(GetDistance(36.74114227294922, 119.14092225294847,  36.70890173661081, 119.12844896818463));
        double[] rs = transBMapPosition(36.699466705322266,119.0972188313802);
        System.out.println("百度坐标:" + rs[1] + "," + rs[0]);
    }
}