经纬度相关的处理

 1.通过经纬度判断两个点之间的距离，这里面的地球半径取得是平均半径，赤道半径和极地半径是不同的，所以取平均。

public class Distance {
    public static final double DEGREES_TO_RADIANS = Math.PI / 180.0;
    public static final double RADIANS_TO_DEGREES = 180.0 / Math.PI;
    //地球半径
    public static final double EARTH_MEAN_RADIUS_KM = 6371.009;
    //地球直径
    private static final double EARTH_MEAN_DIAMETER = EARTH_MEAN_RADIUS_KM * 2;

    /***
     * 距离半径计算方式
     * @param latCenterRad  中心点经纬度
     * @param lonCenterRad
     * @param latVals  目标经纬度
     * @param lonVals
     * @return 两坐标的距离 单位千米
     *
     */
    public static double doubleVal(double latCenterRad, double lonCenterRad, double latVals, double lonVals) {
        //计算经纬度
        double latRad = latVals * DEGREES_TO_RADIANS;
        double lonRad = lonVals * DEGREES_TO_RADIANS;

        //计算经纬度的差
        double diffX = latCenterRad * DEGREES_TO_RADIANS - latRad;
        double diffY = lonCenterRad * DEGREES_TO_RADIANS - lonRad;
        //计算正弦和余弦
        double hsinX = Math.sin(diffX * 0.5);
        double hsinY = Math.sin(diffY * 0.5);
        double latCenterRad_cos = Math.cos(latCenterRad * DEGREES_TO_RADIANS);
        double h = hsinX * hsinX
                + (latCenterRad_cos * Math.cos(latRad) * hsinY * hsinY);

        return (EARTH_MEAN_DIAMETER * Math.atan2(Math.sqrt(h), Math.sqrt(1 - h)));
    }

    public static void main(String[] args) {
        double v = doubleVal(116.34455, 39.954588, 116.31791, 39.9354);
        System.out.println(v);
    }
}

2.根据提供的经度和纬度、以及半径，取得此半径内的最大最小经纬度

public class LngLat_Test {
    private static double PI = 3.14159265;
    private static double EARTH_RADIUS = 6378137;
    private static double RAD = Math.PI / 180.0;

    /// <summary>
    /// 根据提供的经度和纬度、以及半径，取得此半径内的最大最小经纬度
    /// </summary>
    /// <param name="lat">纬度</param>
    /// <param name="lon">经度</param>
    /// <param name="raidus">半径(米)</param>
    /// <returns></returns>
    public static double[] GetAround( double lon,double lat, int raidus)
    {

        Double latitude = lat;
        Double longitude = lon;

        Double degree = (24901 * 1609) / 360.0;
        double raidusMile = raidus;

        Double dpmLat = 1 / degree;
        Double radiusLat = dpmLat * raidusMile;
        Double minLat = latitude - radiusLat;
        Double maxLat = latitude + radiusLat;

        Double mpdLng = degree * Math.cos(latitude * (PI / 180));
        Double dpmLng = 1 / mpdLng;
        Double radiusLng = dpmLng * raidusMile;
        Double minLng = longitude - radiusLng;
        Double maxLng = longitude + radiusLng;
        return new double[] { minLat, minLng, maxLat, maxLng };
    }

    //116.292372,39.956232
    //116.460491,39.966788
    public static void main(String[] args) {
        double lat=39.913833;//纬度
        double lon=116.280423; //经度
        int raidus=1000;//半径（米）
        double[] ds = GetAround(lon,lat, raidus);
        for (double d : ds) {
            System.out.println(d);
        }

    }


}

3.将火星/高德坐标转变成百度坐标

public class GD_2_Baidu {
    /**
     * 
     */
    private static double x_pi = 3.14159265358979324 * 3000.0 / 180.0;
    public  void bd_encrypt(double lng, double lat) {
        try {
            double x = lng, 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;



        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();

        }
    }
}

4.经纬度 的geohash值的取值，当然不同的设置可以有不同的精度

package geoHash; /**
 *@Description: GeoHash实现经纬度的转化
 */

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;


public class GeoHash {
    private LocationBean location;
    /**
     * 1 2500km;2 630km;3 78km;4 30km
     * 5 2.4km; 6 610m; 7 76m; 8 19m
     */
    private int hashLength = 8; //经纬度转化为geohash长度
    private int latLength = 20; //纬度转化为二进制长度
    private int lngLength = 20; //经度转化为二进制长度

    private double minLat;//每格纬度的单位大小
    private double minLng;//每个经度的倒下
    private static final char[] CHARS = {'0', '1', '2', '3', '4', '5', '6', '7',
            '8', '9', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'j', 'k', 'm', 'n',
            'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};

    public GeoHash(double lat, double lng) {
        location = new LocationBean(lat, lng);
        setMinLatLng();
    }

    /**
     * @Author:lulei
     * @Description: 设置经纬度的最小单位
     */
    private void setMinLatLng() {
        minLat = LocationBean.MAXLAT - LocationBean.MINLAT;
        for (int i = 0; i < latLength; i++) {
            minLat /= 2.0;
        }
        minLng = LocationBean.MAXLNG - LocationBean.MINLNG;
        for (int i = 0; i < lngLength; i++) {
            minLng /= 2.0;
        }
    }

    /**
     * @return
     * @Author:lulei
     * @Description: 求所在坐标点及周围点组成的九个
     */
    public List<String> getGeoHashBase32For9() {
        double leftLat = location.getLat() - minLat;
        double rightLat = location.getLat() + minLat;
        double upLng = location.getLng() - minLng;
        double downLng = location.getLng() + minLng;
        List<String> base32For9 = new ArrayList<String>();
        //左侧从上到下 3个
        String leftUp = getGeoHashBase32(leftLat, upLng);
        if (!(leftUp == null || "".equals(leftUp))) {
            base32For9.add(leftUp);
        }
        String leftMid = getGeoHashBase32(leftLat, location.getLng());
        if (!(leftMid == null || "".equals(leftMid))) {
            base32For9.add(leftMid);
        }
        String leftDown = getGeoHashBase32(leftLat, downLng);
        if (!(leftDown == null || "".equals(leftDown))) {
            base32For9.add(leftDown);
        }
        //中间从上到下 3个
        String midUp = getGeoHashBase32(location.getLat(), upLng);
        if (!(midUp == null || "".equals(midUp))) {
            base32For9.add(midUp);
        }
        String midMid = getGeoHashBase32(location.getLat(), location.getLng());
        if (!(midMid == null || "".equals(midMid))) {
            base32For9.add(midMid);
        }
        String midDown = getGeoHashBase32(location.getLat(), downLng);
        if (!(midDown == null || "".equals(midDown))) {
            base32For9.add(midDown);
        }
        //右侧从上到下 3个
        String rightUp = getGeoHashBase32(rightLat, upLng);
        if (!(rightUp == null || "".equals(rightUp))) {
            base32For9.add(rightUp);
        }
        String rightMid = getGeoHashBase32(rightLat, location.getLng());
        if (!(rightMid == null || "".equals(rightMid))) {
            base32For9.add(rightMid);
        }
        String rightDown = getGeoHashBase32(rightLat, downLng);
        if (!(rightDown == null || "".equals(rightDown))) {
            base32For9.add(rightDown);
        }
        return base32For9;
    }

    /**
     * @param length
     * @return
     * @Author:lulei
     * @Description: 设置经纬度转化为geohash长度
     */
    public boolean sethashLength(int length) {
        if (length < 1) {
            return false;
        }
        hashLength = length;
        latLength = (length * 5) / 2;
        if (length % 2 == 0) {
            lngLength = latLength;
        } else {
            lngLength = latLength + 1;
        }
        setMinLatLng();
        return true;
    }

    /**
     * @return
     * @Author:lulei
     * @Description: 获取经纬度的base32字符串
     */
    public String getGeoHashBase32() {
        return getGeoHashBase32(location.getLat(), location.getLng());
    }

    /**
     * @param lat
     * @param lng
     * @return
     * @Author:lulei
     * @Description: 获取经纬度的base32字符串
     */
    private String getGeoHashBase32(double lat, double lng) {
        boolean[] bools = getGeoBinary(lat, lng);
        if (bools == null) {
            return null;
        }
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < bools.length; i = i + 5) {
            boolean[] base32 = new boolean[5];
            for (int j = 0; j < 5; j++) {
                base32[j] = bools[i + j];
            }
            char cha = getBase32Char(base32);
            if (' ' == cha) {
                return null;
            }
            sb.append(cha);
        }
        return sb.toString();
    }

    /**
     * @param base32
     * @return
     * @Author:lulei
     * @Description: 将五位二进制转化为base32
     */
    private char getBase32Char(boolean[] base32) {
        if (base32 == null || base32.length != 5) {
            return ' ';
        }
        int num = 0;
        for (boolean bool : base32) {
            num <<= 1;
            if (bool) {
                num += 1;
            }
        }
        return CHARS[num % CHARS.length];
    }

    /**
     * @param lat
     * @param lng
     * @return
     * @Author:lulei
     * @Description: 获取坐标的geo二进制字符串
     */
    private boolean[] getGeoBinary(double lat, double lng) {
        boolean[] latArray = getHashArray(lat, LocationBean.MINLAT, LocationBean.MAXLAT, latLength);
        boolean[] lngArray = getHashArray(lng, LocationBean.MINLNG, LocationBean.MAXLNG, lngLength);
        return merge(latArray, lngArray);
    }

    /**
     * @param latArray
     * @param lngArray
     * @return
     * @Author:lulei
     * @Description: 合并经纬度二进制
     */
    private boolean[] merge(boolean[] latArray, boolean[] lngArray) {
        if (latArray == null || lngArray == null) {
            return null;
        }
        boolean[] result = new boolean[lngArray.length + latArray.length];
        Arrays.fill(result, false);
        for (int i = 0; i < lngArray.length; i++) {
            result[2 * i] = lngArray[i];
        }
        for (int i = 0; i < latArray.length; i++) {
            result[2 * i + 1] = latArray[i];
        }
        return result;
    }

    /**
     * @param value
     * @param min
     * @param max
     * @return
     * @Author:lulei
     * @Description: 将数字转化为geohash二进制字符串
     */
    private boolean[] getHashArray(double value, double min, double max, int length) {
        if (value < min || value > max) {
            return null;
        }
        if (length < 1) {
            return null;
        }
        boolean[] result = new boolean[length];
        for (int i = 0; i < length; i++) {
            double mid = (min + max) / 2.0;
            if (value > mid) {
                result[i] = true;
                min = mid;
            } else {
                result[i] = false;
                max = mid;
            }
        }
        return result;
    }


//    public static void main(String[] args) {
//        // TODO Auto-generated method stub
//        GeoHash g1 = new GeoHash(39.92116161986104, 116.42291855642424);
////        GeoHash g5 = new GeoHash(40.222910, 116.248980);
//        GeoHash g2 = new GeoHash(39.91217638013896, 116.41120344357577);
////        GeoHash g3 = new GeoHash(40.222002, 116.248203);
////        GeoHash g4 = new GeoHash(40.222112, 116.248383);
//
//        System.out.println(g1.getGeoHashBase32());
//        System.out.println(g2.getGeoHashBase32());
////        System.out.println(g3.getGeoHashBase32());
////        System.out.println(g4.getGeoHashBase32());
////        System.out.println(g5.getGeoHashBase32());
//    }
    public static String getGeoHash(double lng,double lat){
        GeoHash g4 = new GeoHash(lat, lng);
        return g4.getGeoHashBase32();

    }


}