附近商家位置java开发附近定位

根据给定经纬度(lat,lng)求出其左上角(left_top),右上角(right_top),左下角(left_bottom)，右下角(right_bottom)的四个位置。所有在这个区域的范围都在该点附近。 

public class Test {  
    private double latitude;  
    private double longitude;  

    public Location(double latitude, double longitude) {  
        this.latitude = latitude;  
        this.longitude = longitude;  
    }  

    public double getLatitude() {  
        return latitude;  
    }  

    public void setLatitude(double latitude) {  
        this.latitude = latitude;  
    }  

    public double getLongitude() {  
        return longitude;  
    }  

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

}  

Java代码  收藏代码
package com.show.common.util;  

public class LatitudeLontitudeUtil {  

    // http://blog.charlee.li/location-search/  

    /** 地球半径 */  
    private static final double EARTH_RADIUS = 6371000;  
    /** 范围距离 */  
    private double distance;  
    /** 左上角 */  
    private Location left_top = null;  
    /** 右上角 */  
    private Location right_top = null;  
    /** 左下角 */  
    private Location left_bottom = null;  
    /** 右下角 */  
    private Location right_bottom = null;  

    private LatitudeLontitudeUtil(double distance) {  
        this.distance = distance;  
    }  

    private void getRectangle4Point(double lat, double lng) {  

        // float dlng = 2 * asin(sin(distance / (2 * EARTH_RADIUS)) / cos(lat));  
        // float dlng = degrees(dlng) // 弧度转换成角度  
        double dlng = 2 * Math.asin(Math.sin(distance / (2 * EARTH_RADIUS))  
                / Math.cos(lat));  
        dlng = Math.toDegrees(dlng);  

        // dlat = distance / EARTH_RADIUS  
        // dlng = degrees(dlat) # 弧度转换成角度  
        double dlat = distance / EARTH_RADIUS;  
        dlat = Math.toDegrees(dlat); // # 弧度转换成角度  

        // left-top : (lat + dlat, lng - dlng)  
        // right-top : (lat + dlat, lng + dlng)  
        // left-bottom : (lat - dlat, lng - dlng)  
        // right-bottom: (lat - dlat, lng + dlng)  
        left_top = new Location(lat + dlat, lng - dlng);  
        right_top = new Location(lat + dlat, lng + dlng);  
        left_bottom = new Location(lat - dlat, lng - dlng);  
        right_bottom = new Location(lat - dlat, lng + dlng);  

    }  

    public static double hav(double theta) {  
        double s = Math.sin(theta / 2);  
        return s * s;  
    }  

    public static double getDistance(double lat0, double lng0, double lat1,  
            double lng1) {  
        // from math import sin, asin, cos, radians, fabs, sqrt  

        // def hav(theta):  
        // s = sin(theta / 2)  
        // return s * s  

        // def get_distance_hav(lat0, lng0, lat1, lng1):  
        // "用haversine公式计算球面两点间的距离。"  
        // # 经纬度转换成弧度  
        // lat0 = radians(lat0)  
        // lat1 = radians(lat1)  
        // lng0 = radians(lng0)  
        // lng1 = radians(lng1)  

        // dlng = fabs(lng0 - lng1)  
        // dlat = fabs(lat0 - lat1)  
        // h = hav(dlat) + cos(lat0) * cos(lat1) * hav(dlng)  
        // distance = 2 * EARTH_RADIUS * asin(sqrt(h))  

        // return distance  
        lat0 = Math.toRadians(lat0);  
        lat1 = Math.toRadians(lat1);  
        lng0 = Math.toRadians(lng0);  
        lng1 = Math.toRadians(lng1);  

        double dlng = Math.abs(lng0 - lng1);  
        double dlat = Math.abs(lat0 - lat1);  
        double h = hav(dlat) + Math.cos(lat0) * Math.cos(lat1) * hav(dlng);  
        double distance = 2 * EARTH_RADIUS * Math.asin(Math.sqrt(h));  

        return distance;  
    }  

    public static Location[] getRectangle4Point(double lat, double lng,  
            double distance) {  
        LatitudeLontitudeUtil llu = new LatitudeLontitudeUtil(distance);  
        llu.getRectangle4Point(lat, lng);  
        Location[] locations = new Location[4];  
        locations[0] = llu.left_top;  
        locations[1] = llu.right_top;  
        locations[2] = llu.left_bottom;  
        locations[3] = llu.right_bottom;  
        return locations;  
    }  

    public static void main(String[] args) {  
        double lat = 30.500;  
        double lng = 120.500;  
        double distance = 500d;  
        Location[] locations = LatitudeLontitudeUtil.getRectangle4Point(lat,  
                lng, distance);  
        String sql = "SELECT * FROM place WHERE lat > "  
                + locations[2].getLatitude() + " AND lat < "  
                + locations[0].getLatitude() + " AND lng > "  
                + locations[0].getLongitude() + " AND lng < "  
                + locations[1].getLongitude();  
        System.out.println(sql);  

        double lat1 = 30.495503391970406;  
        double lng1 = 120.49261708577215;  
        double d = LatitudeLontitudeUtil.getDistance(lat, lng, lat1, lng1);  
        System.out.println(d);  
    }  
}