谷歌地图偏移校正java

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;


public class AdjustLatLng {
private static int zoom =18;//地图层级
//private static int offsetX = -270;//当前层级下X偏移
//private static int offsetY = 1193;


/**
* 请求谷歌，获取X,Y偏移量
*/
public static double[] request(double lat,double lng){
String path="http://ditu.google.cn/maps/vp?spn=0.0,0.0&z=18&vp="+lat+","+lng;//请求的路径
InputStream is = null;
ByteArrayOutputStream bao = null;
HttpURLConnection urlConn = null;
double[] offsetPix = new double[2];
try{
URL url = new URL(path.toString());
urlConn = (HttpURLConnection)url.openConnection();
urlConn.setRequestProperty("Content-Type","text/xml;charset=UTF-8");  
is = urlConn.getInputStream();
bao = new ByteArrayOutputStream();
byte block[] = new byte[4096];
int read = is.read(block);
while(read != -1) {
bao.write(block,0,read);
read = is.read(block);
}
String shuJu = new String(bao.toByteArray(), "utf-8");
int x = shuJu.lastIndexOf("[");
int y = shuJu.lastIndexOf("]");
//System.out.print(x+","+y);
//System.out.println(shuJu);
if (x > 0 && y > 0) {
String text = shuJu.substring(x + 1, y);


int b = text.lastIndexOf(",");


int a = text.lastIndexOf(",", b - 1);


if (a > 0 && b > 0) {


String offsetPixX = text.substring(a + 2, b);


String offsetPixY = text.substring(b + 2);
//System.out.println(offsetPixX);
//System.out.println(offsetPixY);
offsetPix[0] = Double.parseDouble(offsetPixX);
offsetPix[1] =  Double.parseDouble(offsetPixY);
}
}
} catch(Exception e) {
e.printStackTrace();
return null;
} finally {
try {
if(bao != null) {bao.close();bao = null;}
if(is != null) {is.close();is = null;}
if(urlConn != null) {urlConn.disconnect();urlConn = null;}
} catch(Exception e) {
e.printStackTrace();
}


}
return offsetPix;
}


/**
* 经度转化成像素值
* @param lng
* @param zoom
* @return
*/
public static double lngToPixel(double lng, int zoom) {


return (lng + 180) * (256L << zoom) / 360;


}
/**
* 像素值转化为经度值
* @param pixelX
* @param zoom
* @return
*/


public static double pixelToLng(double pixelX, int zoom) {


return pixelX * 360 / (256L << zoom) - 180;


}
/**
* 纬度转化为像素值
* @param lat
* @param zoom
* @return
*/


public static double latToPixel(double lat, int zoom) {


double siny = Math.sin(lat * Math.PI / 180);


double y = Math.log((1 + siny) / (1 - siny));


return (128 << zoom) * (1 - y / (2 * Math.PI));


}
/**
* 像素值转化为纬度
* @param pixelY
* @param zoom
* @return
*/
public static double pixelToLat(double pixelY, int zoom) {


double y = 2 * Math.PI * (1 - pixelY / (128 << zoom));


double z = Math.pow(Math.E, y);


double siny = (z - 1) / (z + 1);


return Math.asin(siny) * 180 / Math.PI;


}


/**
* 调整后的经纬度
* @param lat
* @param lng
* @return
*/
public static double[] adjustLatLng(double lat,double lng){
double [] offset = request(lat,lng);
double latPixel = Math.round(latToPixel(lat, zoom));
double lngPixel = Math.round(lngToPixel(lng,zoom));
latPixel += offset[1];
lngPixel += offset[0];
double adjustedLat = pixelToLat(latPixel,zoom);
double adjustedLng = pixelToLng(lngPixel,zoom);
double[] adjustedLatLng ={adjustedLat,adjustedLng};
return adjustedLatLng;
}




}