两个经纬度点之间计算距离【经纬度距离计算】
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2024-02-14 22:59:40
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/**
* 测量方法来自百度地图
*/
public class MapDistance {
private double DEF_PI = 3.14159265359; // PI
private double DEF_2PI = 6.28318530712; // 2*PI
private double DEF_PI180 = 0.01745329252; // PI/180.0
private double DEF_R = 6370693.5; // radius of earth
private MapDistance(){}
private static MapDistance instance;
public static synchronized MapDistance getInstance(){
if(instance == null){
instance = new MapDistance();
}
return instance;
}
/**
* 返回为m,适合短距离测量
*
* @param lon1
* @param lat1
* @param lon2
* @param lat2
* @return
*/
public String getShortDistance(double lon1, double lat1, double lon2, double lat2) {
double ew1, ns1, ew2, ns2;
double dx, dy, dew;
double distance;
// 角度转换为弧度
ew1 = lon1 * DEF_PI180;
ns1 = lat1 * DEF_PI180;
ew2 = lon2 * DEF_PI180;
ns2 = lat2 * DEF_PI180;
// 经度差
dew = ew1 - ew2;
// 若跨东经和西经180 度,进行调整
if (dew > DEF_PI)
dew = DEF_2PI - dew;
else if (dew < -DEF_PI)
dew = DEF_2PI + dew;
dx = DEF_R * Math.cos(ns1) * dew; // 东西方向长度(在纬度圈上的投影长度)
dy = DEF_R * (ns1 - ns2); // 南北方向长度(在经度圈上的投影长度)
// 勾股定理求斜边长
distance = Math.sqrt(dx * dx + dy * dy);
return trans(distance);
}
/**
* 返回为m,适合长距离测量
*
* @param lon1
* @param lat1
* @param lon2
* @param lat2
* @return
*/
public String getLongDistance(double lon1, double lat1, double lon2, double lat2) {
double ew1, ns1, ew2, ns2;
double distance;
// 角度转换为弧度
ew1 = lon1 * DEF_PI180;
ns1 = lat1 * DEF_PI180;
ew2 = lon2 * DEF_PI180;
ns2 = lat2 * DEF_PI180;
// 求大圆劣弧与球心所夹的角(弧度)
distance = Math.sin(ns1) * Math.sin(ns2) + Math.cos(ns1) * Math.cos(ns2)
* Math.cos(ew1 - ew2);
// 调整到[-1..1]范围内,避免溢出
if (distance > 1.0)
distance = 1.0;
else if (distance < -1.0)
distance = -1.0;
// 求大圆劣弧长度
distance = DEF_R * Math.acos(distance);
return trans(distance);
}
private String trans(double distance) {
boolean isBig = false; // 是否为大于等于1000m
if (distance >= 1000) {
distance /= 1000;
isBig = true;
}
return (new DecimalFormat(".00").format(distance)) + (isBig ? "千米" : "米");
}
}