java腾讯地图与百度地图坐标转换

/**
	 * 坐标转换，腾讯地图转换成百度地图坐标
	 * @param lat 腾讯纬度
	 * @param lon 腾讯经度
	 * @return 返回结果：经度,纬度
	 */
	public String map_tx2bd(double lat, double lon){
		double bd_lat;
		double bd_lon;
		double x_pi=3.14159265358979324;
	    double x = lon, y = 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);
	    bd_lon = z * Math.cos(theta) + 0.0065;
	    bd_lat = z * Math.sin(theta) + 0.006;

	    System.out.println("bd_lat:"+bd_lat);
	    System.out.println("bd_lon:"+bd_lon);
	    return bd_lon+","+bd_lat;
	}

	/**
	 * 坐标转换，百度地图坐标转换成腾讯地图坐标
	 * @param lat  百度坐标纬度
	 * @param lon  百度坐标经度
	 * @return 返回结果：纬度,经度
	 */
	public String map_bd2tx(double lat, double lon){
		double tx_lat;
		double tx_lon;
		double x_pi=3.14159265358979324;
		double x = lon - 0.0065, y = 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);
	    tx_lon = z * Math.cos(theta);
	    tx_lat = z * Math.sin(theta);
	    return tx_lat+","+tx_lon;
	}