/**
 * 百度摩卡拖坐標與火星坐標的加密解密算法
 * @author XFan
 *
 */
public class Outer {
 private static double lat = 31.22997;
 private static double lon = 121.640756;
 public static double x_pi = lat * lon / 180.0;
 public static void main(String[] args) {
  System.out.println("摩卡坐標經緯度:"+lat+","+lon);
  System.out.println("火星坐標經緯度:"+bd_decrypt(lat,lon));
 }
 //解密成為火星坐標
 public static String bd_decrypt(double bd_lat, double bd_lon) 
 { 
     double x = bd_lon - 0.0065, y = bd_lat - 0.006; 
     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 gg_lon = z * Math.cos(theta); 
     double gg_lat = z * Math.sin(theta);
     return gg_lat+","+gg_lon;
 }
 //加密成為摩卡托坐標
 public static String bd_encrypt(double gg_lat, double gg_lon) 
 { 
     double x = gg_lon, y = gg_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 bd_lon = z * Math.cos(theta) + 0.0065; 
     double bd_lat = z * Math.sin(theta) + 0.006; 
     return gg_lat+","+gg_lon;
 } 
}