地图坐标系转换java版

所属分类：[JAVA] | 创建时间：2014-12-11 | 文章属性：原创 | 文章来源：http://windfly.cn | 作者：windfly

```
/**
	 * Krasovsky 1940<br>
	 * a = 6378245.0 1/f = 298.3 <br>
	 * b = a * (1 - f)<br>
	 * ee = (a^2 - b^2) / a^2;
	 */
	private static double a = 6378245.0;
	private static double ee = 0.00669342162296594323;
	private static double pi = 3.14159265358979324;

/**
	 * GCJ到WGS坐标转换（高德地图为GCJ），较慢，精度高，使用二分极限法
	 * @author DingFengHua
	 * @since 2014-12-9
	 * @param gcjLon
	 * @param gcjLat
	 * @return
	 */
	public static double[] GCJ2WGS_exact(double gcjLon, double gcjLat) {
		double initDelta = 0.01;
		double threshold = 0.000000001;
		double dLat = initDelta, dLon = initDelta;
		double mLat = gcjLat - dLat, mLon = gcjLon - dLon;
		double pLat = gcjLat + dLat, pLon = gcjLon + dLon;
		double wgsLat, wgsLon, i = 0;
        while (true) {
            wgsLat = (mLat + pLat) / 2;
            wgsLon = (mLon + pLon) / 2;
            double[] tmp = WGS2GCJ(wgsLon,wgsLat);
            dLat = tmp[1] - gcjLat;
            dLon = tmp[0] - gcjLon;
            if ((Math.abs(dLat) < threshold) && (Math.abs(dLon) < threshold))
                break;
 
            if (dLat > 0) pLat = wgsLat; else mLat = wgsLat;
            if (dLon > 0) pLon = wgsLon; else mLon = wgsLon;
            if (++i > 10000) break;
        }
        return new double[]{wgsLon,wgsLat};
	}
	
	/**
	 * GCJ到WGS坐标转换（高德地图为GCJ），快速，精度不高
	 * @author DingFengHua
	 * @since 2014-12-9
	 * @param wgLon
	 * @param wgLat
	 * @return
	 */
	public static double[] GCJ2WGS(double wgLon, double wgLat) {
		if (outOfChina(wgLat, wgLon)) {
			return new double[] { wgLat, wgLon };
		}
		double dLat = transformLat(wgLon - 105.0, wgLat - 35.0);
		double dLon = transformLon(wgLon - 105.0, wgLat - 35.0);
		double radLat = wgLat / 180.0 * pi;
		double magic = Math.sin(radLat);
		magic = 1 - ee * magic * magic;
		double sqrtMagic = Math.cbrt(magic);
		dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
		dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);
		return new double[] { wgLon - dLon, wgLat - dLat };
	}
	/**
	 * 设备为WGS,高德地图为GCJ
	 * 
	 * @param wgLat
	 * @param wgLon
	 * @return
	 */
	public static double[] WGS2GCJ(double wgLon, double wgLat) {
		if (outOfChina(wgLat, wgLon)) {
			return new double[] { wgLat, wgLon };
		}
		double dLat = transformLat(wgLon - 105.0, wgLat - 35.0);
		double dLon = transformLon(wgLon - 105.0, wgLat - 35.0);
		double radLat = wgLat / 180.0 * pi;
		double magic = Math.sin(radLat);
		magic = 1 - ee * magic * magic;
		double sqrtMagic = Math.cbrt(magic);
		dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
		dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);
		return new double[] { wgLon + dLon, wgLat + dLat };
	}

/**
	 * 坐标是否在中国范围内
	 * @author DingFengHua
	 * @since 2014-12-11
	 * @param lat
	 * @param lon
	 * @return
	 */
	public static boolean outOfChina(double lat, double lon) {
		if (lon < 72.004 || lon > 137.8347)
			return true;
		if (lat < 0.8293 || lat > 55.8271)
			return true;
		return false;
	}

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.cbrt(Math.abs(x));
		ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;
		ret += (20.0 * Math.sin(y * pi) + 40.0 * Math.sin(y / 3.0 * pi)) * 2.0 / 3.0;
		ret += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0;
		return ret;
	}

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.cbrt(Math.abs(x));
		ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;
		ret += (20.0 * Math.sin(x * pi) + 40.0 * Math.sin(x / 3.0 * pi)) * 2.0 / 3.0;
		ret += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0
				* pi)) * 2.0 / 3.0;
		return ret;
	}
```