百度坐标转换gps坐标工具类

百度坐标和标准的gps坐标有偏差，这里提供一个百度坐标转换为gps坐标的工具类。

package com.smarteye.baidumap;

import com.baidu.location.BDLocation;

public class GlobalTool {
	public final static double a = 6378245.0;
	public final static double ee = 0.00669342162296594323;

	// 判断坐标是否在中国
	public static boolean outOfChina(BDLocation bdLocation) {
		double lat = bdLocation.getLatitude();
		double lon = bdLocation.getLongitude();
		if (lon < 72.004 || lon > 137.8347)
			return true;
		if (lat < 0.8293 || lat > 55.8271)
			return true;
		if ((119.962 < lon && lon < 121.750) && (21.586 < lat && lat < 25.463))
			return true;

		return false;
	}

	public final static double x_pi = 3.14159265358979324 * 3000.0 / 180.0;

	public static BDLocation BAIDU_to_WGS84(BDLocation bdLocation) {
		if (outOfChina(bdLocation)) {
			return bdLocation;
		}
		double x = bdLocation.getLongitude() - 0.0065;
		double y = bdLocation.getLatitude() - 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);
		bdLocation.setLongitude(z * Math.cos(theta));
		bdLocation.setLatitude(z * Math.sin(theta));
		return GCJ02_to_WGS84(bdLocation);
	}

	public static BDLocation GCJ02_to_WGS84(BDLocation bdLocation) {
		if (outOfChina(bdLocation)) {
			return bdLocation;
		}
		BDLocation tmpLocation = new BDLocation();
		tmpLocation.setLatitude(bdLocation.getLatitude());
		tmpLocation.setLongitude(bdLocation.getLongitude());
		BDLocation tmpLatLng = WGS84_to_GCJ02(tmpLocation);
		double tmpLat = 2 * bdLocation.getLatitude() - tmpLatLng.getLatitude();
		double tmpLng = 2 * bdLocation.getLongitude()
				- tmpLatLng.getLongitude();
		for (int i = 0; i < 0; ++i) {
			tmpLocation.setLatitude(bdLocation.getLatitude());
			tmpLocation.setLongitude(bdLocation.getLongitude());
			tmpLatLng = WGS84_to_GCJ02(tmpLocation);
			tmpLat = 2 * tmpLat - tmpLatLng.getLatitude();
			tmpLng = 2 * tmpLng - tmpLatLng.getLongitude();
		}
		bdLocation.setLatitude(tmpLat);
		bdLocation.setLongitude(tmpLng);
		return bdLocation;
	}

	public static BDLocation WGS84_to_GCJ02(BDLocation bdLocation) {
		if (outOfChina(bdLocation)) {
			return bdLocation;
		}
		double dLat = transformLat(bdLocation.getLongitude() - 105.0,
				bdLocation.getLatitude() - 35.0);
		double dLon = transformLon(bdLocation.getLongitude() - 105.0,
				bdLocation.getLatitude() - 35.0);
		double radLat = bdLocation.getLatitude() / 180.0 * Math.PI;
		double magic = Math.sin(radLat);
		magic = 1 - ee * magic * magic;
		double sqrtMagic = Math.sqrt(magic);
		dLat = (dLat * 180.0)
				/ ((a * (1 - ee)) / (magic * sqrtMagic) * Math.PI);
		dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * Math.PI);
		bdLocation.setLatitude(bdLocation.getLatitude() + dLat);
		bdLocation.setLongitude(bdLocation.getLongitude() + dLon);
		return bdLocation;
	}

	public static double transformLat(double x, double y) {
		double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y
				+ 0.2 * Math.sqrt(Math.abs(x));
		ret += (20.0 * Math.sin(6.0 * x * Math.PI) + 20.0 * Math.sin(2.0 * x
				* Math.PI)) * 2.0 / 3.0;
		ret += (20.0 * Math.sin(y * Math.PI) + 40.0 * Math.sin(y / 3.0
				* Math.PI)) * 2.0 / 3.0;
		ret += (160.0 * Math.sin(y / 12.0 * Math.PI) + 320 * Math.sin(y
				* Math.PI / 30.0)) * 2.0 / 3.0;
		return ret;
	}

	public static double transformLon(double x, double y) {
		double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1
				* Math.sqrt(Math.abs(x));
		ret += (20.0 * Math.sin(6.0 * x * Math.PI) + 20.0 * Math.sin(2.0 * x
				* Math.PI)) * 2.0 / 3.0;
		ret += (20.0 * Math.sin(x * Math.PI) + 40.0 * Math.sin(x / 3.0
				* Math.PI)) * 2.0 / 3.0;
		ret += (150.0 * Math.sin(x / 12.0 * Math.PI) + 300.0 * Math.sin(x
				/ 30.0 * Math.PI)) * 2.0 / 3.0;
		return ret;
	}
}