根據一個經緯度,計算出當前經緯度的半徑,可用於打卡,場合。
import com.alibaba.fastjson.JSON;
import java.lang.*;
/**
* @author wangwei
* @version v1.0.0
* @description 經緯度工具類
* @date
*/
public class LatLonUtil
{
private static double PI = 3.14159265;
private static double EARTH_RADIUS = 6378137;
private static double RAD = Math.PI / 180.0;
/// <summary>
/// 根據提供的經度和緯度、以及半徑,取得此半徑內的最大最小經緯度
/// </summary>
/// <param name="lat">緯度</param>
/// <param name="lon">經度</param>
/// <param name="raidus">半徑(米)</param>
/// <returns></returns>
public static double[] GetAround(double lat, double lon, 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 };
}
/// <summary>
/// 根據提供的兩個經緯度計算距離(米)
/// </summary>
/// <param name="lng1">經度1</param>
/// <param name="lat1">緯度1</param>
/// <param name="lng2">經度2</param>
/// <param name="lat2">緯度2</param>
/// <returns></returns>
public static double GetDistance(double lng1, double lat1, double lng2, double lat2)
{
double radLat1 = lat1 * RAD;
double radLat2 = lat2 * RAD;
double a = radLat1 - radLat2;
double b = (lng1 - lng2) * RAD;
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;
s = Math.round(s * 10000) / 10000;
return s;
}
public static void main(String[] args) {
double a = 31.0152789817;
double b = 111.5771484375;
int s = 100;
double[] data = GetAround(a,b,s);
System.out.println(JSON.toJSONString(data));;
}
}