百度坐标转换&计算坐标之前距离

// 坐标转换

GPS转百度

var location = transformFromWGS84ToBaidu(Float,Float);

console.log(location.lat + " _ " + location.lng);

 

百度转GPS

var location = transformFromBaiduToWGS84(Float,Float);

console.log(location.lat + " _ " + location.lng);

 

/**

 * 

 * 计算两个坐标之间距离（米）

 *

 */

public class DistUtil

{

    /**

     * @param args

     */

    public static void main(String[] args)

    {

        double[] a = {84.74704, 44.429556};

        double[] b = {84.721156, 44.450052};

        double[] c = {84.742773, 44.432865};

        

        // a点 -- b点 实时上报c点

        int ac = (int)DistUtil.LantitudeLongitudeDists(a, c);

        int cb = (int)DistUtil.LantitudeLongitudeDists(c, b);

        int ab = (int)DistUtil.LantitudeLongitudeDists(a, b);

        

        System.out.println(ac + "_" + cb + "_" + ab);

        

        if (ac + cb < ab + 10)

        {

            System.out.println("OK");

        }

    }

    

    public static double LantitudeLongitudeDists(double[] a, double[] b)

    {

        return LantitudeLongitudeDist(a[0], a[1], b[0], b[1]);

    }

    

    private static final double EARTH_RADIUS = 6378137;// 赤道半径(单位m)

    

    /**

     * 转化为弧度(rad)

     */

    private static double rad(double d)

    {

        return d * Math.PI / 180.0;

    }

    

    /**

     * 基于余弦定理求两经纬度距离

     * 

     * @param lon1 第一点的精度

     * @param lat1 第一点的纬度

     * @param lon2 第二点的精度

     * @param lat3 第二点的纬度

     * @return 返回的距离，单位km

     */

    public static double LantitudeLongitudeDist(double lon1, double lat1, double lon2, double lat2)

    {

        double radLat1 = rad(lat1);

        double radLat2 = rad(lat2);

        

        double radLon1 = rad(lon1);

        double radLon2 = rad(lon2);

        

        if (radLat1 < 0)

            radLat1 = Math.PI / 2 + Math.abs(radLat1);// south

        if (radLat1 > 0)

            radLat1 = Math.PI / 2 - Math.abs(radLat1);// north

        if (radLon1 < 0)

            radLon1 = Math.PI * 2 - Math.abs(radLon1);// west

        if (radLat2 < 0)

            radLat2 = Math.PI / 2 + Math.abs(radLat2);// south

        if (radLat2 > 0)

            radLat2 = Math.PI / 2 - Math.abs(radLat2);// north

        if (radLon2 < 0)

            radLon2 = Math.PI * 2 - Math.abs(radLon2);// west

        double x1 = EARTH_RADIUS * Math.cos(radLon1) * Math.sin(radLat1);

        double y1 = EARTH_RADIUS * Math.sin(radLon1) * Math.sin(radLat1);

        double z1 = EARTH_RADIUS * Math.cos(radLat1);

        

        double x2 = EARTH_RADIUS * Math.cos(radLon2) * Math.sin(radLat2);

        double y2 = EARTH_RADIUS * Math.sin(radLon2) * Math.sin(radLat2);

        double z2 = EARTH_RADIUS * Math.cos(radLat2);

        

        double d = Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2) + (z1 - z2) * (z1 - z2));

        // 余弦定理求夹角

        double theta = Math.acos((EARTH_RADIUS * EARTH_RADIUS + EARTH_RADIUS * EARTH_RADIUS - d * d) / (2 * EARTH_RADIUS * EARTH_RADIUS));

        double dist = theta * EARTH_RADIUS;

        return dist;

    }

    

}